Bootprints Hiking Guide: Upper and Lower Boulder Lakes in the Eagles Nest Wilderness
July 8, 2017
The Eagles Nest Wilderness Area north of Silverthorne is nearly 133,500 acres of forestlands protected in a primitive condition by Congress in 1976. The wilderness area was carved out of undeveloped and abandoned parts of the Gore Mountain Range. The Gore Range itself was named after Sir George Gore, who hired Jim Bridger to guide him on a hunting expedition through the West in 1854. Gore took 30 wagons and 50 servants on a 6,000-mile expedition through the Rocky Mountains, killing thousands of big-game animals and discovering gold near Piney Lake north of Vail. This initiated a period of exploitation in the central mountains that lasted more than 50 years, including the panning of placers, mining of mineral ores and refining of low-grade ores.
Silver in the hills
Throughout the region at the time, low-grade silver ores were pulverized at stamping mills. Then, silver was extracted by amalgamation using mercury and copper sulfate. After bonding and isolating the silver with mercury, the mercury was vaporized at the expense of mercury equal to or greater than the weight of silver obtained. The resulting contamination at refining locations across the region, as well as leaching of toxic minerals from shaft mines, has damaged the quality of many Colorado waterways for more than a century.
One of the shaft mines in the Eagles Nest Wilderness Area is the Boss Mine at the southern base of Keller Mountain (13,085 feet) at the western end of the Rock Creek Trail. The Boss Mine extracted ore, primarily silver, from 6,000 feet of tunnels dug through narrow veins of ore averaging 3 feet in width. The recovered ore was refined into $220,000 worth of silver during the period from 1882 to 1897.
To Boulder Lake
Boulder Lake and Upper Boulder Lake are popular hiking destinations located on the opposite side of Keller Mountain from the Boss Mine in the Boulder Creek watershed. Boulder Lake is 3 miles north of the Rock Creek trailhead at 9,750 feet. Upper Boulder Lake is a difficult ascent to 11,000 feet, located 3 miles beyond Lower Boulder Lake.
From the Rock Creek trailhead at 9,500 feet, hike west on the Rock Creek Trail for a half-mile to the junction with the Gore Range Trail. Turn right and hike north along the Gore Range Trail, passing wetlands filled with cornhusk lily, cow parsnip, chiming bells, monkshood, false forget-me-not, paintbrush and arnica.
After hiking 2 miles (about one hour) to the ridge of Keller Mountain at 10,100 feet, several large boulders offer seating to rest at this highest point on the trek to Lower Boulder Lake.
Descend from the ridge on a half-mile of switchbacks and cross the bridge over Boulder Creek. The Boulder Creek Trail extends west from a junction immediately across the bridge. For the lake, continue north on the Gore Range Trail and take the next trail west to reach the northern shore of Lower Boulder Lake.
Lower Boulder Lake is a glistening reflection pool with the crest of Keller Mountain dominating the background. The trail continues west on the north side of the lake, passing a wetland area essential for nurturing moose and elk roaming the area.
For an overnight hike, several established dispersed camping sites exist near the shore of Boulder Creek for the next mile of gradual ascent to 10,200 feet.
Onto Upper Boulder Lake
The trail from Lower Boulder Lake to Upper Boulder Lake is much more challenging and dangerous. A meadow opens the forest at 10,200 feet with a log crossing. The trail crosses Boulder Creek to the south side, and then proceeds west beside the stream.
My notes in this difficult stretch from a decade ago bear a strong resemblance to a recent ascent in June 2017, mentioning many dead and down logs across the trail. The trail vanishes or becomes confusing, with several social trails branching off — all equally tempting directions to attack the physical barriers ahead.
On this trail, the pace grinds to less than 1 mile of progress per hour due to pathfinding and scrambling up several cliffs. Since no certain and sustainable trail can be constructed through this steep and narrow watershed, the Forest Service does not maintain a path to Upper Boulder Lake and discourages visitors by not circulating a Recreational Opportunity Guide to the area. Undertake the climb to Upper Boulder Lake at your own risk — and potential reward.
Drive north 8 miles from the Silverthorne interchange with Interstate 70 to mile marker 109 on Highway 9 North. Turn west on Rock Creek Road, across from the Forest Service Blue River Campground. After ascending 1.2 miles, turn left at the winter parking area. Forest Service Road 1350 is reasonably maintained to allow low-clearance vehicles to continue 1.5 miles to the Rock Creek Trailhead. Along the way, there are dispersed camping areas among aspen and lodgepole pine trees and the gurgling, willow-lined shores of North Rock Creek.
Dispersed camping rules advise that campsites must be 100 feet from waterway, trail or road. However, some established yet non-conforming campsites exist. Dispersed campers in the Eagles Nest Wilderness Area should always minimize impact by packing out all trash, avoiding lakeside campsites and not building campfires. Dogs must be kept on leash for the safety of wildlife, other hikers and pets. All motorized and wheeled activities are prohibited in wilderness areas, including mountain bikes. Heavy use of the wilderness has degraded the appearance of areas, permanently compacted soils, sterilized soils with campfires and stripped areas of fuel wood. User abuse encourages policy makers to tighten regulations and close access to damaged areas.
Author Kim Fenske has written extensively on hiking trails throughout Colorado. His writing includes, "Greatest Hikes in Central Colorado: Summit and Eagle Counties," and "Hiking Colorado: Holy Cross Wilderness," available from Amazon Kindle Books.