Olema Creek

Olema Creek
Arroyo Olemus Loke
Olema Creek is located in California
Olema Creek
Location of mouth
EtymologyOlemake is Coast Miwok, Arroyo Olemus Loke a mix of Miwok and Spanish
Native nameOlemaloke (Coast Miwok)
Location
CountryUnited States
StateCalifornia
RegionMarin County, California
Physical characteristics
SourceWestern slope of Bolinas Ridge
 • location2.5 mi (4 km) southwest of Gilroy
 • coordinates37°58′37″N 122°42′27″W / 37.97694°N 122.70750°W / 37.97694; -122.70750[1]
 • elevation1,350 ft (410 m)
MouthConfluence with Lagunitas Creek, 2.5 miles (4.0 km) south of Tomales Bay
 • location
Southwest Point Reyes Station, California
 • coordinates
38°03′51″N 122°48′40″W / 38.06417°N 122.81111°W / 38.06417; -122.81111[1]
 • elevation
3 ft (0.91 m)
Length9 mi (14 km)

Olema Creek is a 12.7-mile-long (20.4 km)[2] northwestward-flowing stream originating on the western flank of Bolinas Ridge, which is part of the Marin Hills, part of the Pacific Coast Ranges mountain system in California, United States. Olema Creek flows to Lagunitas Creek and thence to Tomales Bay and the Pacific Ocean.

History

Olema is probably the name of a Coast Miwok village named "Olemos" or "Olemus" in the baptismal records of Mission Dolores after 1802.[3]

Watershed and Course

The Olema Creek watershed is 14.7 square miles (38 km2), and is the largest undammed tributary of Lagunitas Creek. It flows northwesterly through the Olema Valley along the San Andreas Fault Zone.[4] The creek flows through the small towns of Five Brooks, Olema, and Point Reyes Station where Olema Creek ends at its confluence with Lagunitas Creek.

Ecology and Conservation

The Olema Creek watershed is 99% on National Park Service lands, although 56% of this is under grazing leases.[4]

Olema Creek hosts anadromous coho salmon (Oncorhynchus kisutch) which are federally endangered Central California Coast coho salmon evolutionary significant unit ESU, and steelhead trout (Oncorhynchus mykiss) which are federally threatened Central California Coast Steelhead distinct population segment (DPS).[5] Nineteen percent of the coho salmon spawning in the Lagunitas Creek watershed takes place in Olema Creek.[6] Olema Creek coho salmon were used to genetically rescue Russian River coho salmon suffering from inbreeding depression, resulting in higher fitness of this endangered salmonid in the Russian River.[7]

Olema Creek also hosts multiple other listed species: California freshwater shrimp (Syncharis pacifica), tidewater goby (Eucyclogobius newberryi) and California red-legged frog (Rana draytonii).[4]

The downstream reach of Olema Creek historically meandered through the Olema marsh until the early 1920s. Presently, the channel of Olema Creek is incised several meters below its floodplain, likely triggered by artificial straightening of the channel near its mouth, increasing its gradient.[8]

References

  1. ^ a b U.S. Geological Survey Geographic Names Information System: Olema Creek
  2. ^ U.S. Geological Survey. National Hydrography Dataset high-resolution flowline data. The National Map Archived March 29, 2012, at the Wayback Machine, accessed April 25, 2023
  3. ^ Erwin G. Gudde (1998). California Place Names: The Origin and Etymology of Current Geographical Names. Berkeley, California: University of California Press. p. 268.
  4. ^ a b c Dylan Voeller; David Lewis; Ben Becker; Kenneth W. Tate; Tina Saitone (May 31, 2018). Olema Creek Watershed – Water Quality Analysis and Condition Assessment (PDF) (Report). Sacramento, California: California State Water Resources Control Board. Retrieved April 25, 2023.
  5. ^ "Central California Coast Steelhead". NOAA Fisheries. December 6, 2021. Retrieved April 25, 2023.
  6. ^ Eric Ettlinger; Jonathan Koehler; Kalvin Joe; Emily Cox (November 1, 2022). Adult Salmonid Monitoring in the Lagunitas Creek Watershed 2021–2022 (PDF) (Report). Corte Madera, California: Marin Water. Retrieved April 25, 2023.
  7. ^ Kasey C. Pregler; Mariska Obedzinski; Elizabeth A. Gilbert-Horvath; Benjamin White; Stephanie M. Carlson; John Carlos Garza (2023). "Assisted gene flow from outcrossing shows the potential for genetic rescue in an endangered salmon population". Conservation Letters. 16 (2). doi:10.1111/conl.12934. S2CID 255036654. Retrieved April 25, 2023.
  8. ^ Tina M. Niemi; N. Timothy Hall (1996). "Historical Changes in the Tidal Marsh of Tomales Bay and Olema Creek, Marin County, California". Journal of Coastal Research. 12 (1): 90–102. JSTOR 4298463.