Page Type Page Type: Mountain/Rock
Location Lat/Lon: 37.47760°N / 121.556°W
Additional Information County: Santa Clara
Activities Activities: Hiking
Seasons Season: Spring, Summer, Fall, Winter
Additional Information Elevation: 4089 ft / 1246 m
Sign the Climber's Log


Eylar Mountain is the most northern of the Diablo Range peaks that stand above 4,000 feet. It is also the fourth highest peak in Santa Clara County and is one of a group of five in the county that exceed an elevation of 4,000 feet. The others are Copernicus Peak, Mount Hamilton, Mount Isabel and Pyramid Rock, all located ten to twelve miles southwest of Eylar Mountain and situated within a few miles proximity to one another.
Eylar MountainEylar Mountain summit looking to the southwest

Eylar MountainBurned area near summit of Eylar Mountain

The Summit

A fire road leads directly to the summit where an abandoned, two-story wooden tower still stands. There is also a cement platform or foundation north of the tower. The ground surrounding the tower is littered with worn, weathered lengths of wood and cement blocks and a few small outcroppings of rock. The USGS Eylar Mountain Quadrangle indicates a benchmark which the author of this page was unable to find. However, survey stakes were found north of the tower. One assumes the benchmark is hidden beneath the detritus scattered about or one of many cow-patties in abundance here. Small trees obscure the view-lines but with nominal impact. Because of its height advantage, Eylar Mountain commands a sweeping and far-reaching view in all directions. The entire expanse of Valpe Ridge and the summit of Mount Lewis are viewed directly to the west. Cedar Mountain Ridge occupies the north view. Eight miles to the southwest, Mount Day and Black Mountain stand guard over isolated Alameda Creek Valley. Continuing southwest, the Burnt Hills appear as a chain of furrowed hills and canyons carpeted with dark green and dense chaparral thickets. Further due south, the wide expanse of San Antonio Valley spreads-out like a picturesque diorama. To those with eagle vision, Mount Stakes is visible in the distant southeast, while much closer and directly due east stand Mount Boardman and Mount Boardman North. Mount Oso is easily identified farther east as its summit has a cluster of white communication buildings perched on top.
Eylar MountainSummit of Eylar Mountain.
Eylar MountainOld farming equipment near summit of Eylar Mountain

"Hell of a Country"

William Brewer writing of the view and lands seen from Mount Oso says: "We tied up our mules and climbed the ridge. It was steep and long, but the summit was gained. We found the mountain to be 3,400 feet high. The view was magnificent. Back of the treeless hills that lie along the San Joaquin plain, there rises a labyrinth of ridges, furrowed and separated by deep canyons. These ridges rise 3,200 to 4,000 feet high, with scattered trees over them, sometimes, but not often, with some chaparral. This region is twenty-five to thirty miles wide and extends far to the southwest—I know not how far, but perhaps two hundred miles. It is almost a terra-incognita. No map represents it, no explorers touch it; a few hunters know something of it, and all unite in giving it a hard name. Two different ones, one a companion of old Grizzly Adams, have described it to us as ‘a hell of a country,’ and so far as our observations go they were not far from correct. We got into the margin of it on the west last summer, from the San Jose Valley, and were now peeping into it from the east." [William Brewer, Up and Down California in 1860-1864: The Journal of William H. Brewer. (University of California Press, Berkeley 1966, 1974) pgs. 283-284.]
Eylar MountainThe Burnt Hills
Eylar MountainSign en route to Eylar Mountain

Getting There

Use the driving directions below to reach the parking area south of Turner Gulch. On the west side of Mines Road the slopes have been bulldozed partly clear of brush and trees. Walk to the most northern edge of this area and crawl under the fence that has a small yellow sign indicating buried electrical cable. Go straight up the slope staying north of a gulley. In approximately 50 yards you should find “The Swath” a graded fire break that climbs the steep slope. It connects less than one mile above to a ranching road. Turn right following it northwest. Views begin to open up in all directions as you gain in ridgeline elevation. Pass through patches of forest mixed with an understory of Manzanita and other chaparral shrubs. You will soon pass through two gates. The first encloses land owned by N3 Cattle Company. The second indicates land owned by Biel Property, Inc. Approximately one mile further, Mount Eylar’s summit comes into view. An old viewing tower stands upon it so the route is obvious. You’ll be amazed at the views that surround you.
Eylar MountainGate en route to Eylar Mountain
Eylar MountainGate en route to Eylar Mountain

Driving Directions

William H. Brewer 1859William H. Brewer 1879.
William Brewer & Field PartyWilliam Brewer & Field Party of 1864
Although the trailhead to Eylar Mountain can be accessed by traveling north on San Antonio Road from Mount Hamilton, as well by traveling west on Del Puerte Road off Interstate 5, travel from Livermore provides the quickest route. Exit I-580 eastbound or westbound in Livermore at North Livermore Avenue. Head south and proceed through town (North Livermore Avenue will become South Livermore Avenue in town). Approximately 1.5 miles outside of downtown Livermore turn right at Mines Road. Continue southeast on Mines Road. At mile 20, you’ll pass the designated Alameda & Santa Clara County border crossing. You’ll soon see a cattle corral on the west side of Mines Road and then you will cross the mile 21 marker. Park your vehicle on the east side of Mines Road at the dirt pullout north of Turner Gulch. There is a mailbox just before Turner Gulch Road with the address numbers 54200, which can be see with Google Map's street view. Here is a google link showing where to park

Red Tape

At the time of this writing, Eylar Mountain is private property. To hike here legally, you will need permission from the landowners.


Camping is available nearby at Del Valle Reservoir in Livermore.

External Links

Eylar Mountain Statistics
List of Santa Clara County Peaks
Online version of Eylar Mountains USGS Quadrangle
Another online version of Eylar Mountain USGS Quadrangle
Bob Burd's Trip Report