South County
Do you find the information in this page useful?
Description of the Area
Caswell Memorial State Park (28000 S. Austin Road, Ripon) is one of the best-preserved remnants of riparian woodland and valley oak forest in the San Joaquin Valley. Originally, 134 acres were donated to the people of California in 1950 by the children and grandchildren of Thomas Caswell. With additional state purchases and donations by private contributors, the park was expanded to 258 acres and opened to the public in 1958.
This park is characterized by groves of trees with thick canopies, as well as dense understories of shrubs and hanging vines where birds may forage, find cover, and nest. The magnificent valley oak is chief among the trees that include white alder, box elder, three species of ash, Western sycamore, and Fremont cottonwood. The luxuriant undergrowth is composed of almost wholly native vegetation such as blue elderberry, toyon berry, wild rose, California blackberry, Oregon grape, and California wild grape. At least four species of willow line the riverbanks.
How to Get There
Since this park is located in the southernmost end of San Joaquin County, virtually all birders will be coming down Highway 99 to get there. Take the Austin Road off-ramp [Exit 240] and drive south for five miles, where the road ends at the entrance station. During most months, there will not be a ranger present at the station. The $10.00 per vehicle day use fee (discount for seniors) must be purchased at entry gate. You may pick up a park brochure there, which has a map of the trails. Leave your pay stub on the dashboard of your vehicle and leave nothing of value visible inside your vehicle while you go birding. A ranger may be at the park, living at the staff residence and monitoring the parking lots periodically. This is generally a safe park, although many birders may feel more comfortable going with a small group.
Target Birds
Year-round: Wood Duck, California Quail, Great Horned Owl, Anna’s Hummingbird, Acorn, Nuttall’s, and Downy woodpeckers, Northern Flicker, Oak Titmouse, Bushtit, White-breasted Nuthatch, House and Bewick’s wrens; Lawrence’s Goldfinch, Wrentit, California Thrasher. Note: Great Horned Owls and California Thrashers appear to have moved to the western end of the park, so to look for these species, go along the far end of Fenceline Trail.
Summer: Swainson’s Hawk, White-throated Swift, Western Wood-Pewee, Ash-throated Flycatcher, Black-headed Grosbeak, Lazuli Bunting, Bullock’s Oriole.
Winter: Red-breasted Sapsucker, Ruby-crowned Kinglet, Hermit Thrush, Cedar Waxwing; Orange-crowned, Yellow-rumped, and Townsend’s Warbler; White-crowned and Golden-crowned Sparrow; Dark-eyed Junco. Red-breasted Nuthatch, Brown Creeper, Golden-crowned Kinglet, Varied Thrush, White-throated Sparrow, and Purple Finch are uncommon, but usually present in most winters.
Migrant: Rufous Hummingbird, Pacific-slope Flycatcher; Cassin’s and Warbling Vireos; Swainson’s Thrush, Western Tanager; Orange-crowned, Nashville, Black-throated Gray, Townsend’s, Hermit, MacGillivray’s, and Wilson’s Warbler.
Rarities: There are historical records for Yellow-billed Cuckoo, Bell’s Vireo, and Bank Swallow. Rare or uncommon birds include Eurasian Wigeon, Horned Grebe, Gray Flycatcher, Purple Martin, Hooded Warbler, Magnolia Warbler, Green-tailed Towhee, Bell’s Sparrow, Blue Grosbeak, Summer Tanager, Hooded Oriole.
EBird Hotspot Information
EBird Hotspot – Click Here
Birding At the Site
The gate to the parking lots opens at 8:00 am You may begin by parking at one of the two 15-minute parking spaces for a brief walk down the campground road. There is no day use parking at the campground. Except for the busy spring and summer months, the campground areas will be available for birding. If there are several vehicles and people in the campgrounds, you must stay on the paved road. Do not enter any occupied campground. The campground loop can yield migrant flycatchers, vireos, and warblers in season, as well as resident woodpeckers, sparrows, towhees, and wrens.
After birding around the campground area, return to your vehicle and follow the paved road south until you arrive at the first parking lot. Park by the restrooms and walk over to the river. You may want to take the volunteer trail that leads from the restrooms back north towards the campgrounds. In many winters, a Pacific Wren has been seen there. When you walk south, past the restrooms through the trees, you will arrive at a picnic area. Continue walking on the trail that leads to Willow Beach. The willows harbor many birds there. You may occasionally spot a Belted Kingfisher, Wood Ducks, or Spotted Sandpiper at the river. During the summer, Northern Rough-winged Swallows nest along the opposite riverbank. Note: the opposite bank is Stanislaus Co.
Return to your vehicle and drive south on the paved road to enter the last parking lot. Look for the monument to Estanislao’s Stand. The trailhead leads to six separately named trails, totaling about two miles, which wind to the south and west though the dense woodland. The intersections between trails are well-signed. You are not likely to get lost in the park as long as you keep in mind that all trails lead north back onto Fenceline Trail, which borders an orchard. Once you find yourself on Fenceline, just head east back to the parking lot.
As you walk along River Bend Trail, you will notice the slough on the left. When you get to the spot with two benches, you may see a Green Heron, Wood Ducks, American Wigeon, or other duck species in the slough. In the morning, several Turkey Vultures may be roosting there. From River Bend, you may go along Majestic Oaks Trail, Gray Fox Trail, or Hidden Lake Trail. Some of these trails have interpretive signs and benches along the way.
These trails are wide, mostly graded and well maintained. Poison oak and stinging nettles abound along the edges of the trails, so exercise caution. Insect repellent is recommended during all seasons except the winter. Be alert to the unlikely, but possible, falling of oak tree limbs during high winds. During the spring and summer, ticks, mosquitos and the heat may be so vexing that you may not want to bird there for very long.
More Information
Timing: Visit the website
Parking: Parking available.
Facilities: There are restrooms at the office; ask for permission there. Otherwise, the nearest restrooms are along Thornton Rd near Hwy 12 at any of the service stations or restaurants.
Accessibility: Visit website
Dogs: Dogs are welcome at the park but not allowed on trails, in the river, on beaches, and must always be on a leash.
Bikes: Visit the website
Others: A complete checklist of the birds of Caswell Memorial State Park is available online at the San Joaquin Audubon Society website. This park is under-birded because of its location and day use fee, but hopefully that will change. The tranquil solitude and silence of this beautiful riparian woodland, punctuated only by the calls and songs of birds, are well worth the price of admission.