Almost all field trips are free and open to all, but read the trip outlines to be sure they fit your needs and physical abilities. Bring plenty of water, sunscreen, appropriate trail shoes, a camera, a notepad and lots of enthusiasm. A copy of the recently published Wildflowers of Orange County and the Santa Ana Mts. by Robert Allen and Fred Roberts is also very helpful. If you have other field trip suggestions or would like to lead or assist with a field trip, we would love to hear from you. Please email
Important – always check this website for current trip information.
Rain cancels – check this website after 7 pm the evening before the trip for final weather and trip updates.
Upcoming trips (click on a trip to expand entry and see details). Past trips are at the end:
Rancho Santa Ana Botanic Garden – Sun., Nov. 8. $10 donation requested.
A very special CNPS visit to California's greatest native plant garden, research and teaching facility. Also a great way to kick off the fall native planting season. Rancho Santa Ana Botanic Garden is an 86 acre museum of plants—a living collection. The Garden’s curated living collection contains more than 22,000 plants, representing nearly 1,400 species, hybrids and cultivars of native California flora. To take care of this vast collection, an accession system is vital. Plant curation, like art curation, involves the organization of information about its components. This will be a very special behind-the-scenes visit, just for OC CNPS and not available to most visitors. During our visit we will be guided into many special areas of the facility, where RSA staff will show us some hidden secrets. Stops will include 1) the Seed House representing nearly 2,000 species, 2) conservation work that is on-going in the nursery, 3) a walk to the large "Chia to Chokecherry" exhibit of about 100 ethnobotanical plants and 4) a visit to the garden's extensive Library and Archives. As a finale, we tour RSA’s massive herbarium, which houses over 1.1 million specimens and is the tenth largest in the U.S. Several of these stops will be hosted by RSA experts who will explain their work and answer questions. After the tour be sure to visit the Grow Natives Nursery for your native plant needs..
Meet 9 AM at the entrance booth at Rancho Santa Ana Botanic Garden, 1500 N. College Ave, Claremont. For those who are not already members, there is an $8 entry fee ($6 for seniors or students). For this visit we are also requesting a $10 donation from attendees. This donation will be divided between the botanic garden and OCCNPS, to support both of our efforts. Please bring cash, no credit cards or checks for this donation. Wear comfortable shoes and bring a camera, hat, notepad and enthusiasm.
Physical Difficulty: Easy. Short walking distances. Plant Intensity: High. Time: Approx. 3 hours.
Los Trancos Ridge, Newport Coast – Sun., Jan. 25
Los Trancos Ridge is at the edge of the northernmost portion of Crystal Cove State Park, but is managed by OC Parks. It is seldom visited but a beautiful area, with coastal sage scrub and most importantly, some rare coastal chaparral. The habitat here supports some of the northernmost of the white-flowering Ceanothus megacarpus and a few other specialties. During this first trip of the year we will take an easy hike along the ridge to the North of the canyon, observing and discussing the plants along the way.
Meet at 8 am at the unmarked trailhead on the South side of Vista Ridge Road. The trailhead is about 100 yards South (toward the ocean) of the intersection with Coastal Canyon Drive (or about .75 miles South of Ridgeline Drive). Free parking is available along Vista Ridge Road. Since this is an unmarked entrance to the park, and we have State Park permission, there are no entrance fees or passes needed. Leader: Ron Vanderhoff
Physical Difficulty: Easy to moderate, although the trail is narrow in places. About two miles. Long pants are suggested, to avoid scratching your legs on the chaparral. Trip time: Approximately three hours. Plant intensity: Medium.
The Fossil Reef and Plants of Sheep Hills, Laguna Hills - Sun., March 1
2-28-15 7PM UPDATE: Well, the weather says 30-40% chance of showers tomorrow morning. Nonetheless, I'll be there, hoping for the best. You'll have to make your own decision, depending upon how it looks in the morning. But if you do come, bring a rain jacket just in case, and be prepared that it could still be a washout. We certainly need the rain, so no complaints.
2-25-15 UPDATE: Be sure to check this site after 7 PM the evening before the trip for a final weather and trip update! Nonetheless, a pre-trip today revealed a count of 87 plant species. Several plants are blooming, but the moderate rainfall has also germinated a record number of non-native plants. Added the the list of native plants today were Saltugilia australis (Southern gilia) and Parieteria hespera (Pellitory). This should be a relatively easy trip as we walk the area and loop back to our starting point. Do be aware there are many natural honeybee colonies in this area. Rattlesnakes also inhabit the area, but the cool temperatures would make them quite unlikely.
Fossil Reef is a very unique 17 million year old preserved portion of a formerly submerged tropical reef. This is a tropical shell reef that is associated with fossil rich beach sand. As the only above-ground area of the reef in OC and amazing 48 species of fossil marine vertebrates have been recorded here. Extending for six miles across the Saddleback Valley, but underground elsewhere, this unusual limestone deposit is also found on the Palos Verdes Peninsula, San Clemente Island, Santa Catalina Island, and in Santa Barbara and San Luis Obispo Counties. The exposures here represent the ocean floor, as it existed 17 million years ago. The reef is part of an ancient sea floor that has been exposed by tectonic uplift and weathering processes. This uplift also formed the Santa Ana Mountains and the San Joaquin Hills. The marine muds, that later covered the limestone, contain plankton fossils, shark teeth, fish bones, marine mammal bones and seaweed imprints. A large baleen whale was collected between the park and a nearby high school in 1981. Botanically, the unique geology and limestone soil supports Orange County’s only small colony of Astragalus pomonensis. We will search in this unique area and see what alse we can turn up. Meet at 8 am in front of Aliso Viejo Middle School, 111 Park Avenue, Aliso Viejo. Just find Park Avenue on a map and drive to to the North end of this cul-de-sac and you will see us. From there, we will need to walk a short distance to the reef area and begin our trip. Leader: Ron Vanderhoff.
Physical Difficulty: Easy, with relatively short walking distances and easy terrain. Plant Intensity: Light. Time: Approx. 2 hours.
Elsinore Peak and S. Main Divide Road – Sun., March 22
March 21, 2015 UPDATE: This is the final update. The weather looks good and and we are all set for tomorrow. The general plan is to visit the area toward the base of Elsinore Peak (modest hiking, no really steep sections). Then, we will drive three or four miles back toward Hwy 74 and stop in an area that burned two years ago. After botanizing here foor a bit we will the end the official trip. The drought is still supressing annual flowers, but it is still a bit better than last year.
Following the field trip, for anyone who interested, Ron Vanderhoff is going to then go across Hwy 74 and about 1.5 miles up North Main Divide Road to another burn area from just last summer. It is rich in fire-following annuals, including some beautiful fire poppies.
Elsinore Peak is the southern most of the Santa Ana Mountain peaks and offers an unusual habitat of grasslands with some coastal sage scrub and chaparral. The area near the peak is further unique due to its volcanic history and unusual foundation of basalt rock. The specific stops for our visit will depend upon current conditions and the season’s unpredictable bloom, but we may explore the area just below the peak for spring wildflowers (Fritillaria biflora, Ranunculus, Goldfields, Alliums, Calochortus, Clarkia, Collinsia, Popcorn Flowers, Monkeyflowers, Lupines, Peonies, Sanicula and more). Afterward, we will almost certainly visit the site along S. Main Divide Road of the 2013 “Falls” fire. Last year, this was a highlight of Spring, with large displays of fire-following plants, including thousands of Fire poppies - Papaver californicum, Chorizanthe, Delphinium, Penstemons, Caulanthus, Emmenanthe, Lupinus and many others. Meet 8 AM at the parking lot at Bravo Burgers, 31722 Rancho Viejo Rd., San Juan Capistrano (just off Hwy 74 near Int. 5). Free and open to all. Bring trail shoes, hat, sunscreen, water and lunch if desired. Leader: Ron Vanderhoff. This trip does require a USFS Adventure Pass!
Physical Difficulty: Moderate. No water or restrooms. Plant Intensity: Moderate to high, especially wildflowers. Time: Approx. 3 hours or more depending on the group.
Driving Tour of the Irvine Ranch Conservancy (CNPS Members Only) – Sat., April 11
April 10, 2015 UPDATE: All set for tommorrow morning. See you at 8:30 AM. Should be a perfect day.
The Irvine Ranch Conservancy will be offering its eighth annual CNPS tour of the Irvine Ranch Natural Landmarks with hosts, Jutta Burger and Ron Vanderhoff. Jutta Burger is the Senior Field Ecologist for The Irvine Ranch Conservancy. We will be taking a “diversity drive” along Limestone Canyon, Sand Trap, and the Sinks. Participants will be able to see spring wildflowers, impressive diversity of coastal sage scrub, perennial grassland, and oak woodlands along the western foothills of the Santa Ana Mountains. Hosts will provide a brief history of the land, discussing plant communities and insects associated with them and will have an opportunity to study tracks of our four-legged friends along the way. You’ll also be likely to see or hear two of our iconic butterflies and birds unique to these habitats along the way. Lunch will be provided.We will be driving on bumpy roads in IRC vehicles, including some in an open-air vehicle.
Physical Difficulty: Easy, but includes sometimes rough dirt roads. Short to moderate walking distances. Plant Intensity: Moderate to high, especially wildflowers. Start 8:30 AM, duration approx. 6-7 hours. This trip is limited to the first 20 current CNPS members only. To register please send an email with your name and phone to . A confirmation will be returned for the first 20 CNPS members with meeting directions and other details. Participants will be required to sign a waiver at the beginning of the trip.
Oak Flat, San Mateo Canyon Wilderness – Sun, April 12
April 10, 2015 UPDATE: A pre-trip on Thursday afternoon revealealed about 70 species, although several more likely went undetected. The scenery is wonderful here, although the annuals are about gone for this year due to the hot and very dry weather. We will see several different plant communities, including chaparral, oak woodland, grasslands and coastal sage scrub. Be prepared for about 3.25 miles of hiking, mostly along relatively flat trails. We will begin in some chaparral, then walk thought some of the very scenic grasslands that are bordered by marvelous oaks. Finally, we will finish through a mostly shaded oak woodland section. Be sure to be on time, as we will be entering through a locked gate, then on to a the nice five mile drive to the trailhead.
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 an oasis of grasslands surrounded by beautiful, mature live oak woodlands. A very picturesque area of beautiful, mostly rolling hills that few people ever have an opportunity to experience. Special access to the area will be granted for this group of CNPS members and their guests. We will walk the grasslands and a portion of the oak woodlands, probably in a loop, as we search for Spring wildflowers and other interesting plants.
Meet 8 AM in the parking lot at Bravo Burgers, 31722 Rancho Viejo Rd., San Juan Capistrano (just off Hwy 74 near I-5). Free and open to all. Bring trail shoes, hat, sunscreen, water and lunch if desired. No water or restrooms. Leader: Ron Vanderhoff.
Physical Difficulty: Moderate to strenuous, depending upon how far we go. Plant Intensity: Moderate. Approx. 3 hours.
McGinty Mountain, San Diego County – Sun, April 19
April 18, 2015 UPDATE: All set for tomorrow morning. See you at 7:30 AM. Should be a perfect day. When you arrive at the Park-and-Ride lot on the SE side of Interstate 5 at Junipero Serra Road you will see two lots across the street from each other. We will meet in the Southernmost lot (closer to San Diego). You may want to bring a sandwich or snacks to put in your pack and nibble on during the hike. Be sure to bring water and trail shoes as well.
McGinty Mountain, near Jamul in Southern San Diego County, is a rare habitat with an equally rare collection of plants. The preserve is owned by numerous entities including the California State Department of Fish and Game, the County of San Diego, The Environmental Trust, and The Nature Conservancy. These contiguous parcels constitute a preserve system that is approximately 2,000 acres. Some of the highlight plants we are likely to see include Fish’s milkwort - Polygala cornuta var. fishiae, mint vervain - Verbena menthifolia, San Diego thornmint - Acanthomintha ilicifolia, Parry's tetracoccus – Tetracoccus dioicus, deep pink Acmispon grandiflorus, Dehesa nolina - Nolina interrata, San Diego Viguiera - Bahiopsis laciniata, Cleveland sage – Salvia clevelandii, Gander's ragwort - Packera ganderi, Southern mountain misery – Chamaebatia australis, Mission Manzanita – Xylococcus bicolor and San Miguel Savory – Clinipodium chandleri. Meet 7:30 AM at the Park-and-Ride lot on the SE side of I-5 at Junipero Serra Road, San Juan Capistrano (free). If driving directly to McGinty Mtn. please email rvanderhoff@sbcglobal for details and timing. Bring trail shoes, hat, sunscreen, water and lunch. No water or restrooms. Leaders: Ron Vanderhoff and Jonathan Frank.
Physical Difficulty: Moderate to Strenuous. Plant Intensity: High. Time: about 4 hours, plus drive time.
San Onofre State Beach – Sun, May 3
May 2, 2015 UPDATE: All set for tomorrow morning. See you at 9:00 AM at the old K-Mart parking lot.
This promises to be one of our most informative and educational field trips! With permission from CA State Parks and USMC Camp Pendleton, our group will explore a coastal blufftop with small vernal pools, supporting one of California’s rare species, Pendleton button-celery - Eryngium pendletonense. We will have restoration ecologists on hand to discuss the pools and their restoration as well as CA State Parks environmental scientist Lana Nguyen. After discussing the ecology of the pools and viewing the associated plants, we will turn our attention to other plants of this interesting coastal area.
We will then drive to the far South end of the state park, at Trail #6. At this site we will visit a landmark restoration site which for many years has been employing innovative approaches to remove invasive mustards and other adventitious plants and return the area to a naturally functioning ecosystem. On hand to help explain the effort, which has been underway for more that ten years will be plant ecologist Dr. Ted St. John and David Pryor, senior environmental scientist for CA State Parks. Ted and David will discuss the mustard management, land imprinting, mycorrhizal inoculation and other techniques used on the blufftop restoration.
For those that still want more, we will then visit the site of a March 2014 wildfire and view various wildflowers and perhaps a display of other fire-following plants. Depending upon group interests, a few hearty souls may wish to extend the afternoon into an optional hike down to the coastal beach and adjoining canyons to see the uncommon Emory’s rockdaisy - Perityle emoryi and others. This promises to be a very educational trip, with a chance to interact and talk with some of the areas leading ecologists and restoration experts.
Meet at 9 AM in the parking lot of the former K-Mart (now closed) on Camino de Estrella on the South side of Interstate 5. We will assemble in the parking lot along Camino de Estrella and drive to the State Park from their. If driving South on Interstate 5, exit Camino de Estrella. The K-Mart is on the right side at the bottom of the offramp and very easy to see.
This trip does require an entrance fee to San Mateo State Park! Irregular water and restrooms. Bring lunch and water if attending the optional extended trip. Physical Difficulty: Easy to moderate (moderate for the optional after-trip). Plant Intensity: Moderate. Time: 3 hours with an optional post trip.
Tejon Ranch, Kern County – Sat & Sun. in May. Details TBD
April 18, 2015 UPDATE: This trip has been cancelled.
Assisted by Nick Jensen, Rancho Santa Ana Botanic Garden, Claremont and Bob Allen, co-author of Wildflowers of Orange County and the Santa Ana Mountains.
Encompassing an area of 270,000 acres or 420 square miles, the Tejon Ranch occupies one of the most interesting and complex ecological areas in California. As a result of its unique position at the confluence of four floristic regions, Tejon Ranch is an area of ecological transitions, interesting assemblages of plants from seemingly disparate regions, and quite possibly a whole host of undescribed species, new to science.
As a private, working cattle ranch since the 1840s, Tejon Ranch was almost entirely closed to scientific research until 2008 when the Tejon Ranch Conservancy was created. Under this landmark deal, approximately 100,000 acres of the ranch were placed under conservation easements, and an additional 140,000 acres were reserved from the potential of future development. This amounts to approximately 90% of the ranch being conserved for future generations. As a result of the creation of the Tejon Ranch Conservancy, the ranch is now effectively “open” for scientific research.
Nick Jensen, of The Rancho Santa Ana Botanic Garden, will be our guide for this amazing botanical trip. The goal of Nick’s research at the ranch is to perform a floristic survey leading to a better understanding of the plants on the property and the adjacent ecological regions.Physical Difficulty: Moderate. Plant Intensity: High. Additional details will be posted to www.OCCNPS.org as they become available.
There will be a modest fee and RSVP for this trip. Fees collected will be used to supplement Mr. Jensen’s research efforts at the Ranch.
To the Top of OC: Modjeska & Santiago Peaks, Santa Ana Mountains – Sun., May 24
April 18 UPDATE: This trip has been cancelled. Due to the Sept. 2014 Silverado fire, the Silverado Canyon USFS gate is still closed and is likely to stay this way for another six months. This makes access to Santiago & Modjeska Peaks quite cumbersome. Access permission through this gate has been requested for our group, but could not be confirmed. Stand by - we may post a substitute trip to take its place.
This is a probable trip, but will depend upon interest. 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.
If you are interested in participating, have the appropriate vehicle and have a sense of adventure please send an email to Ron Vanderhoff (). 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.
CNPS RARE PLANT TREASURE HUNT: Santa Ana River Basin – Sun, June 7
This is a rare plant hunt and survey, not a traditional field trip. Please read this description carefully to see if it is right for you.
We will be surveying areas of the Santa Ana River watershed in a focused attempt to relocate some rare plants that were formerly recorded in this region, but have not been seen in several decades. Our two main target species are:
- Eriastrum densifolium ssp. sanctorum – Santa Ana River woolly-star. U.S Endangered, CRPR 1B.1.
- Abronia villosa var. aurita - Yellow hairy sand verbena. CRPR 1B.1.
The Eriastrum has not been recorded in OC since 1929, but there are recent records from as near as Norco, just ten miles upstream. We believe there still might be suitable habitat West of Prado Dam, especially on the alluvial soils and benches in an area known as Horseshoe Bend. In addition to this area, the group will drive a short distance and survey similar habitat east of Gypsum Canyon Road and possibly as far east as Green River Golf Course (the County line). A re-discovery anywhere in this area would be significant.
The Abronia occupies a similar habitat and adds a second rare species to the survey. Historically, this Abronia also occupied sandy alluvial soils in this area, but records are absent since the 1930’s.
With some luck, we might even uncover a population of the locally rare Eriogonum thurberi, which was recorded at Horseshoe bend as recently as 1979. Other interesting, though not necessarily CRPR plants in the area with only historical or very few county records, include Acer negundo, Chaenactis glabruiscula var. lanosa, Ambrosia confertiflora, Eustoma exaltatum, Sagittaria latifolia, Calystegia sepium ssp. limnophila and even the endangered Astragalus brauntonii.
This is a full day in the field, searching for specific taxa. This is not an interpretive/normal field trip, but a focused plant search. We will have fun and learn a great deal, but there is a good to better chance that we will not find these plants.
At the beginning of the trip participants will be shown photos and provided handouts and details of our target plants. Unusual plants seen during the survey will be recorded and carefully vouchered (collected) according to conservation protocols. To learn more about this and other state sponsored CNPS Rare Plant Treasure Hunts visit http://www.cnps.org/cnps/rareplants/treasurehunt/. Leader: Ron Vanderhoff.
Bring trail shoes, hat, sunscreen, water, camera, tablet, pencil/pen; and a field guide, lunch and snacks as desired. Infrequent water or restrooms. Physical Difficulty: Moderate to Strenuous. Plant Intensity: High Tome: all day, but but stay as long as you can. If you are interested in participating, please send an email to Ron Vanderhoff () so that we can plan properly.
Meet 8 am in the MacDonald’s parking lot in the Savi Ranch Center at 22322 Old Canal Rd, Yorba Linda (on the N side of Hwy 91 at Yorba Linda Blvd.).
Nature Gardens of the Los Angeles County Natural History Museum – July 19. Limited to 15 participants.
One of the most ambitious garden projects in Southern California. Dubbed the Nature Gardens, it is a fun and interactive park and habitat area right in the heart of the city. It is stuffed full of a range of garden environments and interactive opportunities for visitors of all ages to watch birds, search for bugs, stroll along a creek, ramble through a grove of trees, and see how urban gardens grow food. Inside this urban wilderness, visitors may spot birds and butterflies, learn to observe and track species, engage in gardening workshops and participate in nature walks.
The newly installed gardens are remarkable. Depending upon her availability, we may be joined by Carol Bornstein, Director of the Gardens, who is also author and one of the most knowledgeable people anywhere on the cultivation of our native flora. Her availablity will likely be a last minute update.
Meet: 9:30 AM at the Museum entrance or 8:15 AM at the Park and Ride at Jeffrey and Walnut, on the South side of the 5 Freeway in Irvine.
Private Tour: Begins 10:00 AM, Sunday, July 19. $18.75 per adult for museum entrance and private tour. $16.00 for seniors or students with ID.
To register please send an email with your name and phone number to . Reservations must be received by July 11. A confirmation with specific meeting directions and other details, such as parking, will be returned for the first 15 people. Participants will be required to sign a waiver at the beginning of the trip.
MUSEUM LINK: http://www.nhm.org/nature/visit/nature-gardens
Parking is available for $10 in the Museum’s Car Park on Exposition Blvd. and Bill Robertson Lane. If the Car Park is full, patrolled lots are also available directly across from the Museum on Bill Robertson Lane for $10 (cash only), as well as in lots throughout Exposition Park.
Physical Difficulty: Easy. Plant Intensity: Medium. Time: 2-3 hours at the garden, plus travel time.
Parking, Passes and Permits
Some trips noted above will require either a US Forest Service Pass, State Parks Pass or an OC Parks Pass. If you are not familiar with these, please read below.
US Forest Service Pass: This is required of any vehicle that parks within a National Forest (such as our Cleveland National Forest), even for a brief moment. Most people purchase an annual pass, called an Adventure Pass, which is a great value. Currently the cost of a pass is $30. One day passes may also be purchased. These may be purchased most easily at sports and outdoor stores such as Big 5, REI, Sport Chalet and Sports Authority. Please purchase a pass in advance - passes are NOT available on the day of the trip. For more information visit http://www.fs.usda.gov/main/r5/passes-permits.
California State Parks Pass: Four California State Parks are in or near the borders of Orange County and require payment of either a day-use fee or use of a pass. Day use fees vary by park and can be paid on the day of the trip at the entrance to the park. Many frequent users prefer to purchase an annual Day-Use Pass. Currently the cost is $195 (senior discounts also). This pass allows unlimited access to all California State Parks. Annual passes may be purchased at most State Park entrances as well as at http://store.parks.ca.gov/park-passes/.
OC Parks Wilderness Pass: Several Regional and Wilderness Parks within the county are owned and operated by OC Parks. These locations require payment of either a day-use fee or use of a pass. Day use fees vary by park and can be paid on the day of the trip at the entrance to the park. Many frequent users prefer to purchase an annual Wilderness Parking Pass. Currently the cost is $55 (senior rates also). This pass allows unlimited access to all inland (not beach) parks, such as Caspers, Irvine Regional Park, Aliso/Wood Canyon, O'Neill, Laguna Coast Wilderness, Whiting Ranch and others. Annual passes may be purchased at most OC Parks facilities. For more information visit: http://ocparks.com/about/fees/pass.