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Jepson Prairie Preserve

Jepson Prairie Preserve



Public Access: Yes

Current and Future Threats: None

Conservation status: Conservation Easement

Adjacent Land Use: Upland Prairie/Meadow/Grassland

Approximate natural buffer width: > 100 ft

Other information: Jepson Praiire Preserve is part of the greater Jepson Prairie Ecosystem which includes over 6000 acres of protected vernal pool and grassland habitat south of Dixon California.



  • Listed on more than one “valuable wetland” list by natural resource agencies or nongovernment organizations.
  • Protects biological diverse wetland flora, fauna and/or their habitat
  • Supports significant numbers of wetland-dependent fauna, such as water birds or fish
  • Rare or unique wetland type within its own biogeographical region. (Meeting this criteria would include, but is not limited to, wetlands with unique hydrology or chemistry that make it rare within its own region)

In 1980 the Nature Conservancy purchased 634 hectares (1,566 acres) of land in Solano County, California to safeguard some of the most intact northern California clay-pan vernal pool and native prairie habitat remaining in the Sacramento Valley. Ownership of the Jepson Prairie Preserve was later transferred to the Solano Land Trust, who presently manage the preserve in cooperation with the University of California Natural Reserve System (UCNRS). The habitat quality and high diversity of flora and fauna have long attracted scientists and researchers to the preserve. Several new taxa have been discovered on the preserve including native solitary bees, Solano grass, and conservancy fairy shrimp. Both Solano grass and conservancy fairy shrimp were discovered in Olcott Lake, a large playa vernal pool that is the centerpiece of the preserve.

Jepson Prairie Preserve includes over 1500 acres of one of the best remaining examples of California Prairie and clay pan vernal pools ramaining the the Sacramento Valley. There are nearly 400 document vascular plant specieson the site includeing 16 species that are rare, threatened, or endangered. The preserves wetalnds and grassland also provide resting, foraging and nesting habitat for over 130 speices of birds and 16 species of reptiles and amphibians including the state andconsevancy fairy shrimp, federally listed California Tiger Salamander. Vernal pools on teh preserve also sprovide habitat for rare, threatened and endangered fairy shrimp including the vernal pool fairy shrimp, they type locality of which is from Olcott Lake on Jepson Prairie Preserve. In addition to providing and protecting vernal pool habitat, the preseve is also jointly managed with the University of California Natural Reserve System and has served asn an outdoor laboraroty, class room and research site for over 25 years. Volunteer docents also lead public tours on weekends throughout the spring months educatoing the general public about the importance of vernal pool ecostsytens and hte unique plants and animals that inhabitat these seasonal wetlands.

Exemplary Ecosystem Services:

  • Maintains ecological connectivity/cohesion
  • Recreation (birdwatching, ecotourism)
  • Education


Approximate size: The Preserve is 634 ha (1566 acres) and includes a large playa vernal pool (Olcott Lake which is over 34 ha)

General wetland characterization: Inland Fresh Seasonally Flooded Basin/Flat

Adjacent Water Bod(ies): Tidal Systems

Name of body of water: Olcott Lake, Barker Slough, Calhoun Cut, Northern Clay Pan Vernal Pools

Surficial Geology: Alluvium derived from sedimentary rock sources

If Adjacent to Stream, insert stream order: Preserve is located in the upper watershed of the San Francisco Bay estuary system.


  • Antioch-San Ysidro complex
  • Pescadero clay loam
  • Pescadero clay
  • San Ysidro sandy loam
  • Solano loam
  • Solano-Pescadero complex


Dominant flora: Eleocharis macrostachya, Plagiobothrys spp. Downingia spp, and Lasthenia spp.

Unique flora: Rare speicies include the federally threatened Neostapfia colusana (Colusa grass) and federally endangered Tuctoria greenei (Greene’s tuctoria)

Dominant fauna: Black neck stilt, Avocet, Canada Goose, California tiger salamander, California ground squirrel

Rare fauna: Conservancy Fairy Shrimp (Branchinecta conservatio) Federally-Listed Endangered and Delta Green Ground Beetle (Elaphrus viridis) Federally-Listed Threatened, among others


Wildlife and Plants of the Jepson Prairie Preserve
National Park Service - National Natural Landmarks

Additional Info

Wetland location : 38.271331 -121.823895


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