Trail Description

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This renowned alpine lake hike is celebrated for its magnificent wildflowers, dramatic waterfalls, excellent fishing, backcountry camping and attractive mountain scenery throughout. Such acclaim draws heavy crowds, so arrive early to secure parking and a measure of solitude.

The trail begins on a moderate grade, rising steadily past the Indian Peaks Wilderness Backcountry board (.4 miles : 10,385’) to the first of several pitched switchbacks (.55 miles : 10,461’). A kaleidoscopic array of summer wildflowers enlivens the verdant hillsides through which you’re passing. In .8 miles (10,595’) the trail levels perpendicularly across notably steep, open slopes with improving views (south) across the valley of Mount Neva (12,814’) and its distinguished ridgeline. A waterfall across this valley – Diamond Lake’s outlet - discloses its location and affords good perspective on the general route you’ll take to reach it.

With little room to maneuver the narrow trail negotiates the midsection of a dramatic waterfall (1 mile : 10,650’), then climbs modestly to the Arapaho Pass – Caribou Pass Trail junction (1.15 miles : 10,752’). Keep straight toward Diamond Lake. The trail glides gently back into serene forest, turns south in a move to cross the valley and drops deliberately to The North Fork of South Boulder Creek (1.7 miles : 10,602’). Just upstream of this crossing is a turbulent waterfall that invites a brief respite before the final push to Diamond Lake.

Wood planks run over an open marsh just beyond the creek crossing (1.85 miles : 10,585’); once through, the trail turns sharply uphill in a dark, north-facing forest. The steep, twisting trail can be obscured by deadfall, runoff and lingering snow well into the summer. After climbing 350’ in just .65 miles, the trail abruptly emerges from the dense timber and levels in a spacious meadow on the northeast fringe of Diamond Lake (2.5 miles : 10,937’).

Raised wooden planks circle this damp expanse to the Devils Thumb Trail connection (2.55 miles : 10,939’), just beyond which a few easy steps in a thinning alpine glade lead to Diamond Lake (2.65 miles : 10,940’).

Diamond Lake occupies a large, uncommonly flat basin near treeline; with few terrestrial obstructions the area and aforementioned meadow are easily explored, though you’ll likely get a bit wet doing so. Follow backcountry campsite access trails to and across Diamond Lake’s scenic outlet stream to sweeping views of the basin and Continental Divide. Continue along the lake’s west shore to its lively inlet, and an informal route that leads to seldom visited Upper Diamond Lake.

GPS Coordinates - DATUM WGS84

• N39 59.714 W105 38.052 - Fourth of July Trailhead

• N40 00.036 W105 38.346 - .55 miles : Begin switchbacks

• N40 00.197 W105 38.616 - 1.0 miles : Cross mid-section of steep falls

• N40 00.252 W105 38.785 - 1.15 miles : Arapaho Pass Trail junction

• N40 00.191 W105 39.234 - 1.7 miles : Bridge over North Fork of S. Boulder Creek

• N40 00.102 W105 39.142 - 1.85 miles : Marshy travel beyond creek crossing

• N39 59.859 W105 38.979 - 2.25 miles : Steep climb to lake

• N39 59.701 W105 38.898 - 2.55 miles : Devils Thumb Trail junction

• N39 59.649 W105 38.945 - 2.65 miles : Diamond Lake

• N39 59.648 W105 38.876 - Diamond Lake : Backcountry Campsite #9

• N39 59.616 W105 38.861 - Diamond Lake : Backcountry Campsite #10

Worth Noting

• The Fourth of July Trailhead is named so because the lakes and high passes it accesses are typically not clear until after 'The Fourth of July'. Locals have played on this name and claim its origin is tied to its magnificent wildflowers that are reminiscent of fireworks on 'The Fourth of July'. Both interpretations are valid: anticipate lingering snow throughout the summer on shaded slopes, and a bar-none wildflower display once it clears.



• In .75 miles from the trailhead a false switchback bears left off the trail. Take note of this, as it can easily be mistaken for the real trail - especially on the return route.



• Diamond Lake is stocked with Rainbow, Brook and Cutthroat trout.



• Diamond Lake is a popular destination reached by a heavily used trail artery. Get an early start to avoid peak-season congestion. Parking is limited and fills up very quickly on weekends.



• After passing the Hessie Turnoff, the road which continues to the 4th of July Trailhead can be rough. 4WD or all-wheel drive and high clearance is recommended.

Camping and Backpacking Information

• Permits are required for all overnight campers June 1 - September 15.



• Permits are required year-round for day and overnight use by large groups (8+) or organizational groups such as scouts, churches, schools and hiking clubs.



• Group size is limited to 12 people or people and packstock combined.



• Campfires are prohibited east side of the Continental Divide, as well as Caribou Lake, Columbine Lake, Gourd Lake, Crater Lake and in the Cascade Creek drainage above Cascade Falls.



• Pets must be on a handheld leash at all times.



• Camping is permitted only at designated campsites in the Diamond, Jasper, Crater and Caribou Lakes Backcountry Zones.



• Camping is prohibited in the Four Lakes Backcountry Zone (Mitchell, Blue, Long, Isabelle) May 1 - Nov 30.



• Camping is prohibited within 100’ of lakes, streams and trails.



• Packstock are prohibited in the Four Lakes Backcountry Zone, in the Cascade Backcountry Zone above Cascade Falls and on the Diamond Lake Trail #975.

Fishing Information

Directions to Trailhead

Diamond Lake is accessed from the Fourth of July Trailhead in the Indian Peaks Wilderness near Nederland, Colorado.

From downtown Nederland, go north on Highway 72 for .5 miles to County Road 130 and make a right. You will see a sign for Eldora Ski Resort at this junction. Continue on Highway 130 through the town of Eldora, just past which it becomes a dirt road (4 miles). Continue on the dirt road (past the Hessie Trailhead) another 4.8 miles and take the right fork at the Buckingham Campground up into the designated parking area. Though suitable for most 2WD cars in good condition, the road between the Hessie turnoff and Fourth of July Trailhead can be rough. High clearance vehicles are recommended.

Contact Information

Boulder Ranger District
2140 Yarmouth Avenue
Boulder, CO 80301

Visitor Information
Phone: 303.541.2500