| Las Trampas Peak | |
|---|---|
| La Sierra de Las Trampas | |
 Las Trampas Peak in the early spring near Alamo, CA | |
| Highest point | |
| Elevation | 556 m (1,824 ft) |
| Coordinates | 37°50′00″N122°03′53″W / 37.8332594°N 122.064685°W /37.8332594; -122.064685 |
| Geography | |
 | |
| Location | Contra Costa County, CA |
| Country | United States |
| State | California |
| county | Contra Costa County |
| Geology | |
| Rock type | sedimentary |
Las Trampas Peak is a 1,827 ft (557 m) peak in theInner Coast Ranges in westernContra Costa County, California, in theSan Francisco Bay Area.[1]
The name "Las Trampas" or "the traps" in Spanish, is derived from the indigenousSaclanBay Miwok peoples' technique of using the area's steep canyons to trap herds ofTule elk and other game species for hunting.[2]
Las Trampas Peak and its surrounding environs are located in theInner Coast Ranges in theSan Francisco Bay Area'sContra Costa County, more specifically in theBerkeley Hills subrange.
The peak is the apex and terminus of an approximately 8 mile-long north-south running ridge composed ofMiocene marinesedimentary rock, known asLas Trampas Ridge.[1]
Las Trampas Creek and its tributaryGrizzly Creek begin on the mountain. Las Trampas Creek is one of the largest sub-watersheds within theWalnut Creek Basin, comprising an area over 17,000 sq acres in size.[3]
Like much of Contra Costa County, Las Trampas peak and its surroundings are largely composed offossiliferous sedimentary rocks from theGreat Valley Sequence.[2] These formations have been heavily altered by millions of years of faulting and rifting, a process that is still ongoing.[4]
The region around Las Trampas Peak is tectonically active, with earthquakes being a common occurrence.
Certain bands in the area contain abundant fossils of prehistoric sea life from theMiocene epoch (~23 mya to ~5 mya)[4][5]
Due to its location within a protected wilderness area,Las Trampas Regional Wilderness, Las Trampas Peak and its surrounding hills are home to many species of wildlife includingColumbian black-tail deer,Coyotes,Bobcats and numerous species of birds.[2]
The north slope of the mountain is thickly forested withCalifornia Coast Ranges mixed evergreen forest, dominant trees includeCoast Live Oak,Valley oak andcalifornia bay among others.
The exposed south-facing slope of the mountain is covered inChaparral.
The east and west sides of the mountain are both mixtures of forest, scrub and grassland, largely depending on the local geology.[4]