Most field trips are free and open to all, but read the trip outlines for parking/entrance fees or pass requirements and be sure they fit your physical abilities. Bring plenty of water, sunscreen, appropriate trail shoes, a camera, a notepad and lots of enthusiasm. These are CA native plant field trips focused on the interpretation, identification and appreciation of our diverse flora and the ecosystems they support. We use botanical terms, discuss plant communities, plant ecology, invasive plants and especially native plant identification. Past trips are at the end of the list. Questions, leadership opportunities and suggestions should be sent to .


Trips change. Always check this page after 7 PM the evening before a trip for updatesRain cancels.

Past Trip Descriptions For summaries of completed trips, plus many species lists, please see the Past Trips  section in the Field Trip drop-down menu

San Onofre State Beach, Trestles and the San Mateo River – Sun, Apr 22

Mouth of San Mateo Creek

April 20 UPDATE: The trip looks good. A site check today has prompted a change for the second stop. Instead of visiting the east end of Christianitos Road, we will visit a more colorful area of the burn, at the east end of La Pata Road. This will be a good trip, with lots of variety.

This is a two part trip to the southernmost border defining Orange County and San Diego County. The main portion will be a visit to the mouth of San Mateo Creek. We will walk under the freeway and along the path used by some of the world’s best surfers and to the famous trestles area, talking about the plants and rare habiitat as we go. When we get to the beach we will take a peek at the freshwater estuary and explore the dune plants and a few of the plants of the coastal strand. We will look for a few plants of the southernmost colony of Acmispon junceus in the U.S., growing some 30+ miles from its nearest neighbor (watch out for the trains). Then can either walk back the way we came or if the group feels a bit more adventurous, we will walk South along the upper beach looking at more plants and then, after a half mile or so, cut through the vegetation along one of the surfer paths. We would then walk back to our cars via the old El Camino Real, which gives a really good overview of this entire area.
For those that have had their fill we will bid adieu. For the rest we will get in our cars and make a short drive to the east end of Christianitos Road and park a bit before the entry gate to USMC Camp Pendleton. Here, we will be within the scar from this summer’s ‘Christianitos’ wildfire. There should be lots of annual wildflowers and will be quite a different experience than the coastal portion.
David Pryor, the well-known retired Senior Biologist for CA State Parks, will co-lead this trip. He will discuss the natural history of the area, provide insights about its plants and biology and share many of his personal experiences (and maybe even a couple of surfer stories). Leaders: Dave Pryor and Ron Vanderhoff.
Meet 9 AM at the corner of Christianitos Road and El Camino Real, San Clemente. Free parking is available on both Christianitos Road and El Camino Real, but is often taken by surfers. Pay parking is available in the State Parks parking lot, adjacent to the Car’s Jr. Bring comfortable shoes, water, camera, hat, notepad and enthusiasm.

Physical Difficulty: Moderate. The total trip is about 2 to 4 miles, depending on the groups desires. Come for all or a half-trip. Rustic porta-potties (usually) at Trestles. Plant Intensity: Medium to high. Time: Approx. 3+ hours.

Catalina Island with the Catalina Island Conservancy – April 28-29. Limited Attendance.


April 9 UPDATE: This trip is now full. We are checking with the Conservancy about the possibility of additional spaces. Reservation requests are now be placed on a stand-by list.

A very special visit, hosted by the Catalina Island Conservancy, to see the native plants and explore the special ecology of one of California’s most cherished locations.

An overnight trip to the back country of Santa Catalina Island. We will leave Newport Beach on the Catalina Flyer on Saturday and return on the late Sunday boat. While on the island, we will be transported by Catalina Island Conservancy vehicles and hosted by their biologists, Julia Parish and Peter Dixon.

As we travel the backcountry we will visit several botanical points of interest throughout the island. Particular attention will be paid to the island endemics and a variety of habitats. The exact itinerary will be decided based upon bloom at the time of the trip. At each of the stops we will hike/walk various distances on varied terrain. Our driver will remain at the vehicle, so those that are not wishing to participate in the hike can explore in the vicinity of the bus on their own.

Saturday night we will stay at the renovated Blackjack Campground toward the center and high point of the island. Large, rigid tents which accomidate up to thirty people each will be our excellent facilities for the night. Tiered bunk-type beds are available for everyone. The campground includes complete cooking facilities, hot and cold potable water, a refrigerator and all the pots, pan, plates and utensils needed for dinner. Toilets and a hot shower are also available. Camping has never been so easy.


$30 per person. This is a great value and doing a trip of this quality on your own would cost considerably more. With these funds, OC CNPS will be making a donation to The Catalina Island Conservancy to support their outstanding conservation, restoration and stewardship activities. Checks or cash will be collected at Avalon prior to beginning the tour. Make checks payable to OC CNPS. In Avalon each participant will also be required to sign an OC CNPS liability waiver, acknowledging and accepting responsibility for any risks, including trips and slips, rattlesnakes, poison oak, etc. and of course the island’s bison population.

How to RSVP

This trip is limited to the first 22 reservations and will strictly be on a first come-first serve basis. To reserve your spot, send an email to as soon as possible. Include your name, the names of all participants and each person’s phone number and email address. You do not need to be a member of CNPS to attend (although we would love you to join). Unfortunately, pets and young children are not allowed.

Getting to the Island

Transportation to the island and back is the responsibility of each participant. We will take The Catalina Flyer out of Newport Beach. Please book your own ticket! The boat leaves the dock at 9 AM on Saturday April 28 and arrives at Avalon at 10:15 AM. The return boat leaves Avalon on April 29 at 4:30 PM and arrives Newport at 5:45 PM. Please book your ticket quickly, in order to secure your spot (but not before you send your RSVP to and receive a confirmation). You can book online here. Normal adult fare is $70 round trip, with discounts for seniors.

What to Bring

Bring normal field equipment for the days. This includes good trail shoes or hiking boots, layers of clothes (it can become suddenly windy and/or cold on the island), possibly rain protection, a hat, sunscreen, camera and daypack. Bring enough water for the day, although water will be available on the bus. Optional items include field guides, binoculars and camera.

For lunch on Saturday we will stop at the Catalina airstrip where a small café has sandwiches and other food (although you can pack your own if you prefer). Otherwise, bring food for all other meals, especially dinner Saturday evening and breakfast and lunch on Sunday. Pack a few snacks as well, as you prefer. Pots and pans, plates and cups, eating utensils and everything you will need for your Saturday dinner will be available at the campground – just bring food. Note, propane and other fuel is NOT permitted on the Catalina Flyer, but you won’t need it anyway.

Bring a sleeping bag for the bunks in the tents and a hand help flashlight or battery operated camp lamp. For even more information on what to bring and the camping/sleeping arrangements see this from the Conservancy.

What to Do

RSVP as soon as possible (see above). This trip will sell out, don’t be left out. Book your boat tickets on the Catalina Flyer before these sell out (but not before you send your RSVP to and receive a confirmation).

Any questions can be sent to . See you on beautiful Catalina Island.

More information about the Catalina Island Conservancy can be found here.

Fossil Reef and Plants of Sheep Hills, Laguna Hills – Sun, May 6

Fossil Reef is a unique 17 million year old preserved portion of a submerged tropical reef. 48 species of fossil marine vertebrates have been recorded here. Extending for six miles across the Saddleback Valley, this unusual limestone deposit is submerged everywhere, except for a few spot, such as here and on the Palos Verdes Peninsula, San Clemente Island, Santa Catalina Island, and in Santa Barbara and San Luis Obispo Counties. These exposures represent an ancient ocean floor, as it existed 17 million years ago. The marine muds associated with these rocks contain plankton fossils, shark teeth, fish bones, marine mammal bones, and seaweed imprints – and even a large baleen whale that was uncovered nearby in 1981. The Fossil Reef area was recently included as part of Aliso-Wood Canyons Wilderness Park. Aliso Creek also meanders through the area and both the wetlands of the creek and the upland areas are part of a significant restoration project. More information is available here.

Botanically, this unique geology and limestone soil supports Orange County’s only small colony of Astragalus pomonensis, while the adjoining riparian portions of Aliso Creek support additional plants and a fragile ecosystem. We will search for plants in the unique area and see what we can turn up.

Josie Bennett is the Restoration Manager for Laguna Canyon Foundation and a native plant expert. She has extensive experience with the natural history of  Orange County, especially its plants, plant communities, insects, amphibians, reptiles and birds. Prior to joining the LCF, Josie worked at the Irvine Ranch Conservancy and the CA State Parks. Meet 9 AM on the street in front of Aliso Viejo Middle School, which is adjacent to Aliso Viejo Community Park. The school address is 111 Park Avenue, Aliso Viejo (Map). From there we will walk a short distance to the field trip/reef area. Leaders: Josie Bennett and Ron Vanderhoff.

Free and open to all. Physical difficulty: Easy, with relatively short walking distances and easy terrain. Plant Intensity: Light. Time: Approx. 2+ hours.

Wildflower Showcase, Irvine Ranch Conservancy Seed Farm Open House – Sat, May 12, RSVP at Let's Go Outside

Mar 24 UPDATE: This trip is now open for reservations. See below.

The Orange County Chapter of the California Native Plant Society, and the Irvine Ranch Conservancy invite you to join them from 10am-2pm as they celebrate Orange County native wildflowers at the Conservancy’s native seed farm. This event is a great way to learn more about OC CNPS, IRC, and the work each organization is doing to conserve, protect, and restore native wildflowers in Orange County. The 8-acre native seed farm currently grows 45 local plant species, each providing seed used to support ecological restoration locally. Expect many of them to be in full bloom for this event, which will be opened by brief presentations from OC CNPS and Conservancy staff, followed by a picnic lunch. After lunch, guests are invited to stroll the grounds at their own pace, or join a guided walking tour, on which they’ll learn about some of the amazing local flora being grown on the farm. OC CNPS will also be presenting on various local engagement opportunities, including information about field trips and their upcoming native garden tour. If you enjoy native wildflowers, good people, and outdoor fun, this event is for you! Parking is limited and carpooling is recommended.

Two sessions are available, a morning session from 9:30-11:00 and an afternoon session from 12:00-1:30. Please RSVP at Free. Reservation spaces are limited.

To the Top of OC: Modjeska & Santiago Peaks, Santa Ana Mountains – Sun, May 27

Samtiago Peak from Modjeska Peak

This is a probable trip, but will depend upon interest and vehicle availability. From the end of Silverado Canyon Road we would drive up Maple Springs Truck Trail to Main Divide Road. From there we will drive toward Modjeska Peak and hike about a half mile to the summit. Then, we will return to the cars and drive on to the top of Santiago Peak. Stops will be made at important botanical sites along the way. This is a unique trip, but not for the meek. The roads are rocky, with lots of ruts and require careful driving. Four-wheel drive is not required, but only high clearance SUV’s or trucks should consider this. There are many plant specialties in Orange County that are only found at these higher altitudes and we will hope to find many of these. Leader: Ron Vanderhoff.

The upper portions of Santiago and Modjeska Peak hold many botanical highlights - many species not seen anywhere else in Orange County.

If you are interested in participating, have the appropriate vehicle and have a sense of adventure please send an email to . If there is enough interest I will send details and we will do it. No water or restrooms. Physical Difficulty: Moderate, but quite difficult roads. Plant Intensity: High. Time: Most of the day.

Temple Hill and Hobo Ridge from Moulton Meadows Park – Sun, June 3

Niguel Hill to the Ocean

A great walk with great views along a portion of the Southern Ridge of Aliso Canyon. Experience a unique but rapidly diminishing coastal chaparral plant community with lots of specialties like Comarostaphylos (summer holly), Ceanothus megacarpus (big pod manzanita), Adenostoma fasciculatum var. obtusifoloium (San Diego Chamise) and a rare population of Verbesina dissita (big-leaf crown beard).  We will begin at Moulton Meadows Park and proceed south along the ridge trail towards Temple hill.

Meet 9 AM Moulton Meadows Park in south Laguna Beach.  Take South Coast Hwy to Nyes Pl., turning left on Balboa Ave until you reach the park. Street parking is free along Balboa Drive (Map). Bring comfortable shoes, water, camera, hat, notepad and enthusiasm. The new book Wildflowers of Orange County and the Santa Ana Mountains is a great field guide for this trip, bring it along.

Physical Difficulty: Moderate, but steep, rocky sections. The total trip is only about 2.5 miles, but these are two or three areas that are steep, uneven, rocky and easy to slip - more of a rut than a trail. If you have trouble going up or down 200 meter inclines you will have trouble. Plant Intensity: Medium. Time: Approx. 3 hours.

The Pebble Plains and Cushenbury Canyon, San Bernardino Mts. – Sun, June 10

The Rare Pebble Plains Habitat

The Big Bear area has a wealth of interesting plants that are unique to high elevations. This is a great area to visit in the summer after wildflowers in Orange County have faded from the heat. Pebble Plain is part of the Baldwin Lake Ecological Reserve. The area was once a glacier lake (Pleistocene era 10,000 years ago). It consists of unique soils composed of quartzite pebbles that were deposited over eons and prevented conifers from taking seed. Pebble Plain is home to 17 protected plant species and 4 rare kinds of butterflies, 3 of which are found nowhere else in the world.

We will also visit Cushenbury Canyon (Cactus Flats), about 10 miles from Baldwin Lake. The rocky carbonate soils of this area support some uncommon species. Cushenbury carbonate flora includes the federally endangered Cushenbury Milk Vetch (Astragalus albens), Cushenbury Oxytheca (Acanthoscyphus parishii var goodmaniana), Cushenbury Buckwheat (Eriogonium ovalifolium var vineum), San Bernardino Mountains Bladderpod (Physaria kingii ssp bernardina), and Parish's Daisy (Erigeron parishii). Meet at the intersection of forest road 3N03 and Highway 18, about half-way up Cushenbury grade. There is a large turnout on the east side and a sign that says "Cactus Flats". High clearance vehicles will be more comfortable on the road, but passenger cars are possible.

Leader: Diane Etchison. Meet at 6:30 at the Caltrans Park-and-Ride Lot at 2555 Tustin Avenue, Orange (SE corner of Lincoln Ave. and Tustin Ave.). Map. Do not be late - we will be leaving promptly at 6:30 AM. Or meet at the Baldwin Lake Ecological Reserve parking area just off Hwy 18 at the north end of Baldwin Lake (a few miles west of the junction with Baldwin Lake Road). It may be hard to find. There is a single small (closed) nature center just off Hwy 18. Bring hat, sunscreen, water and hiking shoes. The drive time is approximately 2.5 hours one-way.

Physical Difficulty: Moderate. Bring hat, sunscreen, water and hiking shoes. Plant Intensity: moderate to high.

Fall Color Trip: Harding Canyon, Santa Ana Mountains – Sun, Nov 18

Harding Canyon Fall Colors

Enjoy the relaxing calmness and fall color of the beautiful and biologically rich Harding Canyon creek trail.  An interesting mix of coast sage, chaparral and Riparian woodland highlight this species-rich walk.  A short walk up the Harding Truck trail leads to the canyon which should be mostly dry this time of the year.  A nice diversity of trees can be found including California ash (Fraxinus dipetala), Arizona ash (Fraxinus velutina), California bay (Umbellularia californica), and Big-leaf maple (Acer macrophyllum).  There will also be a chance to see a few uncommon shrubs such as Nevin's brickllebuch (Brickellia nevinii) and Fish's milkwort (Polygala cornuta var. fishiae).

Meet 9:00 am at the parking lot just right of the Tucker Wildlife Sanctuary, obeying the signs of appropriate parking in the area. Take E. Santiago Canyon Road from either the N or S and turn onto Modjeska Canyon Road leading directly to the parking lot (Map).  Leaders: Jonathan Frank and Ron Vanderoff.

Physical Difficulty: Moderate.  Bring hat, sunscreen, camera, wildflower book/notepad, water and hiking shoes/boots. Limited water or restrooms. Plant Intensity moderate. Time: About 2 .5 hours.


Past Trips

Fungus Foray at Oak Flat with Joanne Schwartz – Sun, Jan 14

Jan 11 UPDATE: Unfortunately. due to the lack of sufficient rain, we have been forced to cancel this trip. Please continue to visit this site frequently for other possible additions or changes to our 2018 field trips.

Joanne Schwartz, a mushroom expert and OC CNPS member, will lead a hunt for interesting mushrooms and fungus within the beautiful oak forests, chaparral and sage scrub habitats of the Oak Flat area. Joanne will explain the differences in the fungus parts and how they reproduce from spores spread by wind, animals, water and insects. Fungus are important t to the ecology of our local wildlands in many ways and without their decomposing and symbiotic characteristics the world would be a very different place. Joanne will demonstrate environmentally friendly methods and tools used to study fungi. Although principally a mushroom and fungus trip, we probably will not be able to avoid pointing out a few of the interesting native plants of the area as well.

Oak Flat (actually a series of several flats) is at the Western edge of The San Mateo Canyon Wilderness and accessed by a locked/private gate off Hwy 74. This seldom visited area is a spectacular oasis of grasslands surrounded by beautiful, mature live oak woodlands. A very picturesque area with access to the area granted for this group. Meet 8 AM in the parking lot at Bravo Burgers, 31722 Rancho Viejo Rd., San Juan Capistrano (just off Hwy 74 near I-5). Map. Free and open to all. Bring trail shoes, hat, sunscreen, water and lunch if desired. No water or restrooms. Leader: Ron Vanderhoff.

Joanne Schwartz is an amateur mycologist and local mushroom expert. She has collected and photographed fungi throughout the world and has participated in field studies in Peru and Bolivia as well as California’s redwood forests.

Important Note: Mushroom are particularly dependent upon winter rainfall for the best hunting. If rains do not cooperate, the date of this trip may be adjusted. Please check this website for any last minute updates.

Free and open to all. Physical Difficulty: Easy to moderate. Bring a hand lens. Approx. 3 hours.


The “Other” Plants: Bryophytes of the San Juan Loop Trail – Sun, Jan 21

With bryophyte expert, Dr.
Paul Wilson

Jan 17 UPDATE: All is set. The weather should be amazing. Be sure to bring some water and a hand lens if you have one. See you all on Sunday!

Paul Wilson, professor of biology at California State University Northridge and a founding member of the CNPS Bryophyte Chapter will lead a fascinating exploration of the non-vascular plants of Orange County. The San Juan Loop Trail is a 2.3-mile path that loops around the back of a hill and past San Juan Falls, a 15-foot drop. It passes through a moist, cool and shaded canyon that should provide plenty of bryophytes for us to examine. We will search the fallen trees, the soil, the rock faces and other surfaces for these amazing plants.

Participants will also be provided with a colorful pictorial guide to many of the bryophytes of this trail and area.

Meet at 9 AM at the trailhead. The trailhead is off the Ortega Highway (SR 74), 19.5 miles from the San Diego Freeway and on the east side of the large parking area just across the road from the Candy Store. Or meet 8 AM in the parking lot at Bravo Burgers, 31722 Rancho Viejo Rd., San Juan Capistrano (just off Hwy 74 near I-5). Map.

We recommend that you purchase the pass in advance from Big 5, Sport Chalet, REI, or most large sports retailers, since the Candy Store may not be open when we arrive. Trip Leader: Paul Wilson. This trip does require a USFS Adventure Pass! Details here.

Physical Difficulty: Moderate. Limited water or restrooms. Bring hat, sunscreen, camera, notepad and water. A magnifying glass is highly recommended. Trip time: approximately three hours. Plant intensity: Medium.

Baker Canyon, Irvine Ranch Natural Landmarks – Fri, Feb 23, RSVP through IRC website

Fritillaria (Chocolate lily) in Baker Canyon

A Friday trip! Between Silverado Canyon and Black Star Canyon, Baker Canyon is a very special place, well insulated and protected from much of the outside world. A part of the Irvine Ranch Natural Landmark, it is only accessible to the public through docent-led events like this. Enjoy views of the Santa Ana Mountains, as well the wildflowers and plants of oak-shaded Baker Canyon and the ridges above. The focus of this walk will be California Lilacs (Ceanothus). There are at least 3 species of Ceanothus in Baker Canyon. Other possible early-blooming plants that might be seen here include Chocolate Lily (Fritillaria biflora) and Palmer's Grapplinghook (Harpagonella palmeri). This will be a  3-4 mile loop hike with a gradual climb to a final elevation of 1370 ft. (elevation gain about 460 ft.), with beautiful views at the top. This event requires reservations made through the IRC website: This will be an 8 AM start. Check the website 1-2 months prior to the event to book your reservation. There is a cap on the number of participants, first come-first serve. Leader: Diane Etchison.

Free and open to all, but RSVP is required (see above). Physical Difficulty: Moderate. Bring hat, sunscreen, camera, wildflower book/notepad, water and hiking shoes/boots. No water or restrooms. Plant intensity: Moderate. Trip time: approximately3.5 hrs.

Portuguese Bend and the Palos Verdes Peninsula Sun, Mar 4

Palos Verdes Penninsula

Mar 3 UPDATE: As you would expect, the area is quite dry this year and annual flowers are almost non-existant. Nonetheless, we will enjoy the rest of the flora and the great scenary. Depending upon the desires of the group, we may shorten the first stop and add another stop, which will take us down a sea bluff path to the beach. It should be an enjoyable trip

The first 300-400 meters of the first stop is fairly steep uphill, thereafter, the trip is moderate up and down and rolling elevations. The trail will be wet from the rain, so good hiking shoes are suggested.

Our first field trip to this very exciting area, filled with botanical highlights. We have been guided to the vest spots by Neil Uelman, a naturalist/biologist with the Palos Verdes Peninsula Land Conservancy. We will begin the trip by exploring the Forrestal Canyon area, home of the only mainland colony of the very rare Catalina Island Crossosoma, a beautiful large shrub that we will unfortunately only be able to see in the far distance. Many other plants of the area will be pointed out and discussed, as well as the areas other unique natural features. After exploring this area we will drive a few miles to our second stop at the Douglas Trail in another protected portion of the peninsula. We will walk the nice trail here and discuss more plants and natural history and complete the official portion of the field trip.

There is much more to see in the area and we encourage attendees to stay for the afternoon and do more exploration. For those interested, a few of us may take a walk down the Palos Verdes bluffs to the beach to view Dudleya virens and other coastal bluff specialties. Finally, we may make a very quick and easy stop to see a small colony of Lycium brevipes var. hassei that is overlooking the Pacific Ocean. This species was thought to be extinct, but was “re-discovered” just 40 years ago.

The Palos Verdes Peninsula Land Conservancy preserves undeveloped land throughout the peninsula. The conservancy’s mission is to create and manage large blocks of natural open space where native plants and animals can thrive. Meeting detail and directions will be posted soon. Leaders: Kent Henry, Ron Vanderhoff.

Meet at the Pirate trailhead on Forrestal Drive near Pirate Drive at 9 am. Or, at 8 AM, we will meet at the Dunkin Donuts at Talbert and Brookhurst in Fountain Valley. From there, drive North on the 405 to the 110 South. Exit Gaffey. Left on Gaffey, Right on 25th. 25th changes into Palos Verdes Drive. Right on Forrestal Drive.

The Douglas Trail is 9 miles away from Forrestal Drive. Turn right on Palos Verdes Drive. Right on Via Montemar. Right on Via Del Monte. Right on Paseo Del Sol. The trailhead is halfway through the curve.

Physical Difficulty: Moderate, except for a steep first 300-400 meters. Approximately three to four miles on trail. Bring hat, sunscreen, camera, wildflower book/notepad, water and hiking shoes/boots. Limited water or restrooms. Plant Intensity medium to high. Time: 3-4 hours.

Caspers Wilderness Park Sun, Mar 11

Mar 10, 3 PM UPDATE: This trip is cancelled. Unfortunately, due to the rain, OC Parks will likely close the trails for a couple of days.

Casper’s Wilderness Park is the Jewel of the Orange County Park system, including 8,000 acres and a wide array of habitats. This walk will head up the Loskorn Trail to the East Ridge Trail, then back again by way of the Starr Rise and Bell Canyon trails for a distance of 3.5 miles. Warning: the Loskorn Trail is steep and narrow with steep drop-offs in places. There will be an optional side trip up the Quail Run Trail to look for Palmer's Grapplinghook (Harpagonella palmeri) on the West Ridge Trail.

Possible wildflowers at this time of year include Clematis pauciflora (Ropevine), Dodecatheon clevelandii (Padre's Shooting Star), Harpagonella palmeri (Palmer's Grapplinghook), Lasthena gracilis (Slender Goldfields), Paeonia californica (California Peony), Caulanthus heteropyllus (San Diego Jewel Flower), Camissoniopsis strigulosa (Sandysoil Suncup), Pseudognaphalium leucocephalum (Sonora Everlasting), and lots of Lupines. Near the top of the Loskorn trail there should be a variety of ferns, bryophytes and Dudleyas. At this time of year open areas may be covered with Calandrinia ciliata (Red Maids). When these flowers open after noon, they form a carpet of red.

Meet at 8 am at the end of Caspers Park road near the windmill. Directions: From 5 freeway, exit Ortega Highway, and go east 8 miles. The entrance to Casper’s is prominently marked on the left. There is a day use fee of $5 per car or free with an OC Parks Pass (more info here). Maps and directions are available at the entrance kiosk as well. Wear sturdy shoes, a hat and sunscreen. Bring hiking poles if you use them and plenty of water. Restrooms and water at the trailhead, but not on the trail. Leader: Diane Etchison.

Physical Difficulty: Moderate, approximately three and a half miles on trails. Bring hat, sunscreen, water and hiking shoes. Portapotty at the staging area.  Plant Intensity: Moderate. Time: About 3 hours.

Water Canyon Natural Preserve, Chino Hills State ParkSun, March 25. RSVP Required and Limited Attendance.

Water Canyon

Mar 24 UPDATE: This trip is GO! The park and trails will be open on Sunday. We still have space, so send an RSVP below for directions. 9 AM start.

A wonderful trip into one of the most scenic and remote parts of Chino Hills State Park. With assistance from Robin Huber, a volunteer at the park, our group will venture into the rugged Water Canyon Natural Reserve. As we make our way up into the canyon, climbing over fallen branches and navigating around trees and cacti, you will feel miles away from any kind of civilization.  The sounds – which include woodpeckers, squirrels and more – are just as much of the attraction here as the plants, which will be thoroughly discussed, with identification tips as well.

The steep-walled canyon, located in the southeast arm of the park, winds through a riparian woodland lush with willow, sycamore, oak, and protected native walnut trees. The hiking-only trail follows the north grassland slope near the shady canyon bottom, heading upstream through the narrow, pristine canyon.

This trip is will be strictly limited to the first 20 people. RSVP's should be sent by emailing your name, phone number and number of attendees to . Directions to the 9 AM meeting location will be sent to the RSVP’s Leaders: Ron Vanderhoff and Robin Huber.

Free and open to all, but RSVP required and space is limited. State Parks does have a small $5 entry fee per vehicle (details here.). Physical Difficulty: Moderate to moderate-strenuous, in some portions with rocky and boulder strewn areas on a narrow semi-overgrown trail. Expect 3.5 to 4 miles. No water or restrooms. Plant Intensity: Moderate to high. Time: Approx. 3 hours or more depending on the group.

Physical Difficulty: Moderate, approximately three to four miles on trail. Bring hat, sunscreen, camera, wildflower book/notepad, water and hiking shoes/boots. Limited water or restrooms. Plant Intensity: moderate to high. Time: About 3 hours.

Whitewater Preserve with OC CNPS and the Wildlands Conservancy – Sun, April 1. Limited Attendance.

Mar 18 UPDATE: This trip is now open for reservations. See below.

Whitewater Canyon Preserve

Details are still pending, but we are working to arrange a special two-part docent led walk of this unique natural area. The first half involves an easy two mile walk up Whitewater Trail to a location known as Red Dome, then back. All along the way we will observe and discuss the large variety of native plants of the area. The habitat blends the species from the lower Sonoran Desert region with those from the higher elevation Mojave Desert, with a few chaparral plants thrown in. region. This portion likely be led by CNPS plant experts. The second half will be near the Conservancy Headquarters, including the former trout ponds and the sensitive riparian natural areas in the area. This second portion would likely be hosted by Wildlands Conservancy Staff. Probably about four hours. Following the trip attendees are free to explore more of the area on their own or drive a short distance to other interesting botanical hotspots in the area, such as Big Morongo Preserve, Palm Canyon, Tahquitz Canyon or Andreas Canyon.

More information about The Wildlands Conservancy and the Whitewater Preserve can be found here.

This trip is will be strictly limited to the first 15 people. RSVP's should be sent by emailing your name, phone number and number of attendees to . Directions to the 9 AM meeting location will be sent to the RSVP’s.

Driving Tour of The Irvine Ranch Natural LandmarksSun, April 8. CNPS Members Only. RSVP required.

Mar 18 UPDATE: This trip is now open for reservations. See below.

Weir Canyon

The Irvine Ranch Conservancy will be offering its ninth annual CNPS tour of the Irvine Ranch Natural Landmarks on Sunday, April 8th with hosts Jutta Burger and Ron Vanderhoff and long-time IRC volunteers. We will be taking a “post-fire recovery” drive, probably up Weir Canyon and Blind Canyons (or possibly Gypsum Canyon). Participants will learn about fire cycles and succession in our Mediterranean climate, will enjoy the spring wildflower bloom that is encouraged by fire, and will be able to observe the effects of too frequent fire on vegetation. Participants will have the opportunity to learn about specific plant species and insects and will have an opportunity to study tracks of our four-legged friends along the way. A simple lunch will be provided.

Dr. Jutta Burger, Senior Field Ecologist from the Irvine Ranch Conservancy, will once again offer CNPS a special trip through the natural areas of The Irvine Ranch Natural Landmarks. CNPS members will visit some of OC’s most important and best protected natural resources. This is a driving tour, on conservancy vehicles, along uneven dirt roads.

This is nearly a full day trip. Portable restroom availability at beginning and end only. This trip is strictly limited to the first 20 CNPS members. RSVP's should be made through a non-public page on the IRC Let's Go Outside activities page. Directions to the parking and starting location will be available during registration process. This will be an 8:30 AM start and approximately a 2:30-3:00 PM finish.

Physical Difficulty: Easy, but includes lots of bouncing around on rough dirt roads. Short to moderate walking distances. Includes lunch. Plant Intensity: Moderate to high, especially wildflowers. Time: Approx. 6-7 hours.

Audubon Starr Ranch – Sun, Apr 15. Limited Attendance. CNPS Members Only. CANCELLED

Audubon Starr Ranch

April 3 UPDATE: Unfortunately, due to a serious injury we have been forced to cancel this trip. Hopefully, we will visit again sometime in the future.

Starr Ranch Sanctuary is a 4,000 acre preserve nestled in the foothills between Casper’s Park, the Cleveland National Forest and the developments of Dove Canyon and Coto de Caza, and operated by the National Audubon Society. For this very special visit we will board sanctuary vehicles and travel with ranch staff to various areas of the property in search of interesting plants of the grassland, coastal sage scrub, chaparral and oak woodland plant communities within the sanctuary. This trip is limited to 15 CNPS members.

Starr Ranch Sanctuary offers volunteer, educational and research opportunities for all age and experience levels. The natural resources here are well preserved and protected. Sandy DeSimone lovingly handles all the land management, research and education on the property, while Pete DeSimone manages the property. Their innovative approaches to wildlands management are extraordinary and will be explained and demonstrated during the visit. For more information about the ranch visit and for a complete plant list of the property visit

Limited restroom and water availability. Picnic tables are available, so bring a picnic lunch to enjoy following the tour.

This trip does require advance registration. This trip is strictly limited to the first 18 CNPS members. RSVP's should be sent by emailing your name, phone number, CNPS membership status and number of attendees to . Directions to the 8 AM meeting location will be sent to the RSVP’s.

Physical Difficulty: Moderate, but includes bouncing around on uneven roads. Plant Intensity: moderate to high. Time: About 3+ hours. 

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