American pika
Ochotona princeps
MorningMiddayAfternoon
Photo: NPS Photo, Rocky Mountain NP — public domain
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Indian Peaks · Hard
Lake Dorothy
The Indian Peaks' highest named lake at 12,061ft via Arapaho Pass
Indian Peaks Wilderness
Distance7.1mi round trip
Elevation1,945ft gain
High point12,061ft summit
Typical time4–5.5hours
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The Indian Peaks' highest named lake at 12,061ft via Arapaho Pass. Editorial intro forthcoming.
Trip facts
Typical duration4–5.5hours
Trailhead10,100ft elevation
High point12,061ft summit
Dogs: leashes required.
How you'll find it
From Nederland, take CO-119 south 0.5 miles, turn west onto Boulder County Road 130 toward Eldora. Continue through Eldora; pavement ends, follow the rough dirt road 5 miles to the Fourth of July Trailhead. Free parking — arrive before 6am summer weekends.
Drive time
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We'll calculate drive time + a leave-by recommendation to beat the lot fill.
What you'll get
- 12,061ft summit lake — highest named lake in the Indian Peaks Wilderness
- Trail climbs to Arapaho Pass (11,906ft) on the Continental Divide
- Passes the historic Fourth of July Mine ruins at 11,245ft
- Sustained alpine exposure — a real Continental Divide day with no permit required
- Connects to Caribou Lake and Arapaho Glacier for ambitious day-link options
What locals know
Practical-craft notes for this specific trail — timing, route, photo, etiquette.
Trail tips
- Timing
Summer-window-only — late June through September
Lake Dorothy at 12,061ft holds snow most of the year. The realistic summer window is late June through mid-September. Outside that, expect snow-covered talus and ice.
- Route
Past Diamond Lake on the Arapaho Pass Trail
From Fourth of July Trailhead, follow Arapaho Pass Trail past the Diamond Lake junction (stay right). Continue 1.5mi over Arapaho Pass to Lake Dorothy. Total 8mi RT with 1,300ft of gain.
- Gear
Trekking poles + microspikes — alpine year-round
Even in peak summer, snowfields linger on the Arapaho Pass climb. Trekking poles essential for the descent; microspikes useful for shoulder-season ice.
- Weather
Above treeline 80% of the route — storms are existential
The Arapaho Pass crossing has zero protection from lightning. Building cumulus by 11am means turn-around time. Pre-dawn start (5am from trailhead) is the safe approach.
- Photo
Pawnee Peak and the divide from the pass
From Arapaho Pass itself (12,750ft), the view east toward Pawnee Peak and the Continental Divide is one of Colorado's best high-passes. Bring an ultrawide; the scale is hard to capture otherwise.
Where you'll start
Lake Dorothy shares the Fourth of July Trailhead with Diamond Lake — free, no permit, but small lot and a rough dirt-road approach. 90+ minutes from Boulder; arrive by 6am summer weekends. The 8-mile out-and-back puts you at 12,061ft — Indian Peaks' highest named lake — so plan around afternoon storms.
Parking cost
Free
Overnight
Allowed
Lake Dorothy is the closest named alpine lake to Arapaho Pass — overnight allowed at trailhead for Indian Peaks backpacking permits.
Park entrance
Free
Restrooms
Vault toilets
Fills by
6am summer weekends — extremely competitive
Cell service
No signal
What's at the trailhead
- Restrooms — Vault toilets
- No potable water — bring your own from town
- Information kiosk
- No cell service — share plans + ETA with a contact before driving in
If the lot is full
Walk-in from the access road below the trailhead when the lot is full.
Access road
Final 5 miles past Eldora are rough dirt — high-clearance vehicle strongly preferred. 4WD recommended after rain.
Vehicle security
Moderate break-in risk reported — stash valuables out of sight before arriving.
When to go
Highlighted months offer the best conditions.
Who shares the trail
At 12,061ft, Lake Dorothy is full alpine — pikas and marmots define the talus, white-tailed ptarmigan camouflage against the tundra, and the occasional mountain goat or bighorn shows on the upper slopes above the pass.
- Common
CommonYellow-bellied marmot
Marmota flaviventris
MorningMiddayAfternoonPhoto: USFWS — public domain
RareWhite-tailed ptarmigan
Lagopus leucura
Year-roundYear-round alpine specialist — perfectly camouflaged (white in winter, mottled brown in summer). Look on the upper Arapaho Pass slopes.
Photo: Andy Reago & Chrissy McClarren, CC BY 2.0 — Wikimedia Commons
RareMountain goat
Oreamnos americanus
Photo: USFWS — public domain
What to watch for
What to watch for
- Extended exposure above treeline — afternoon lightning can end a summit day fast
- High-altitude illness common at 12,000ft+ for sea-level visitors
- Trail crosses snowfields into July — traction recommended early season
- Weather flips fast above 11,500ft — turn back if afternoon clouds build
- Mountain goat habitat above the pass — keep 25+ yards distance
- Trailhead road rough on low-clearance vehicles — high-clearance preferred
On the map
Overnight camping
Lake Dorothy is the highest legal camping in the Fourth of July zone — flat areas just below the lake's outlet make legal sites (200ft from water). Bear-canister required. Most overnight users push through to Lake Dorothy specifically for the alpine experience.
Type
Dispersed backcountry
Water source
Lake Dorothy itself + Arapaho Pass inlet creek; all alpine sources require treatment.
Food storage
Bear-resistant canister REQUIRED. At 12,000ft black bears are rare but not absent; canister covers all wildlife (marmots love unattended food).
Fire policy
Campfires PROHIBITED above treeline. Stoves only.
Trail-tested picks for Lake Dorothy
Curated for this trail's terrain, elevation, and typical conditions.
More routes from the same lot
Same parking, same logistics — if your plans need to flex, here's what else is reachable from Fourth of July Trailhead.
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