Observatory Rock Trailhead

Page Type Page Type: Trailhead
Location Lat/Lon: 39.25960°N / 105.6967°W
Additional Information County: Park
Additional Information Elevation: 9400 ft / 2865 m

Getting There

The Trails Illustrated Map #105 – Tarryall Mts. / Kenosha Pass would be very helpful for navigating to the trailhead.


Head west on US 285 passing over Kenosha Pass. Just over 4 miles west of the Pass turn south (left) on Park County 77 in the small community of Jefferson. Continue south on 77 until you come to the Tarryall Reservoir. Just south of the reservoir, turn right onto Forest Service Road (FSR) 23.


Head west on US 24 to the small community of Lake George. Shortly after crossing a young South Platte River, turn north (right) on Park County 77. Continue north on 77 until you come to the Tarryall Reservoir. Just south of the reservoir, turn left onto Forest Service Road (FSR) 23.

FSR 23 is passable to most vehicles although a high clearance vehicle would be best. After a few miles you will veer right onto FSR 146. Follow FSR 146 past the south side of Eagle Rock. Eagle Rock is a great Class 2 scramble via it’s southwest ridge and a great warm-up for Observatory Rock. At less than two miles down FSR 146 you will turn right onto FSR 834 which is posted as a dead-end. Some folks in passenger cars may wish to park here and begin hiking. Observatory Rock is now quite obvious to the north.

FSR 834 first heads northeast down into Berkey Gulch. The road gradually turns north and then west. At about 2 miles from FSR 146 the road reaches the bottom of Swigler Gulch. At this point there are three choices. Left heads west up into Swigler Gulch. Right is a continuation of FSR 834. Straight leads up through a nice aspen forest to the base of Observatory Rock. Continue straight until you enter a clearing surrounded by aspen at the south base of the Rock. This is the trailhead.

The access roads may not be passable in winter or after a heavy spring snow – check with the Forest Service.

Destinations Accessible from Observatory Rock Trailhead

Observatory Peak from the...

Observatory Rock

Nearby Campgrounds

There are several Forest Service Campgrounds located along Park County 77. To the south is the Spruce Grove and Twin Eagles Campgrounds. Packer Gulch Campground is located at Tarryall Reservoir along FSR 23.



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