Longs Peak is the tallest mountain in Rocky Mountain National Park at 14,255 feet, and its standard route — the Keyhole Route — is one of the most demanding non-technical hikes in Colorado. This isn't a casual day hike; it's a full mountaineering-style objective that happens not to require ropes, on a good day, in the right season.
Quick Facts
- Distance: About 14.5 miles round trip.
- Elevation gain: Roughly 5,100 feet.
- Time: Most hikers take 10–15 hours car to car; experienced parties can do it faster, but budget a full day.
- Difficulty: The hardest standard-route hike in the park — exposed Class 3 scrambling near the summit, with serious fall potential.
- Permit: None required for a day hike. A wilderness permit is required only if you camp overnight at the Boulder Field (these fill up months in advance). The Longs Peak Trailhead is outside the park's Timed Entry reservation area.
Is Longs Peak Right for You?
Be honest with yourself here. The Keyhole Route involves exposed scrambling, steep drop-offs, and loose rock, in an environment where afternoon weather can turn dangerous fast. It's not a good first 14er, and it's not a route to attempt if you're not comfortable with exposure. Building experience on easier Class 2 peaks first is the standard advice from guides who lead this route.
The Route, Section by Section
Trailhead to the Boulder Field
The hike starts in forest, climbs through a series of switchbacks, and breaks above treeline well before the halfway point. The Boulder Field, at roughly 12,700 feet, is where most parties take their final real rest before the technical section begins — and it's also the designated overnight camping area for anyone splitting the hike over two days with a wilderness permit.
The Keyhole
A distinctive rock formation that gives the route its name. Passing through it marks the transition from a strenuous hike to genuine Class 3 scrambling on the mountain's west side.
The Ledges, the Trough, the Narrows, and the Homestretch
These four sections make up the technical heart of the climb — narrow ledges with exposure, a steep gully (the Trough) requiring hand-and-foot scrambling, a narrow traverse (the Narrows) with significant drop-offs, and a final steep slab (the Homestretch) to the summit. Painted bullseyes mark the route in several spots, but route-finding still matters, especially in poor visibility.
When to Go
The ideal window is mid-July through early September, when the upper route is typically dry and free of snow and ice. Outside that window, the Keyhole Route effectively becomes a technical mountaineering objective requiring an ice axe, crampons, and the skills to use them — not a hike.
Start Before Dawn
Nearly everyone who attempts Longs Peak starts between 1 and 3 a.m. Two reasons drive this: it lets you summit and get back below treeline before early-afternoon thunderstorms, which are common and dangerous on an exposed summit, and it spreads out the crowds on the technical sections, where passing other parties on narrow ledges is genuinely hazardous.
What to Bring
- A headlamp with spare batteries (you'll start in the dark).
- Layers — temperatures at the trailhead and the summit can differ by 30°F or more.
- More water than you think you need; there's no reliable water source once you're above the Boulder Field.
- A firm turnaround time, decided before you start, based on weather — and the discipline to actually turn around if you hit it.
Bottom Line
Longs Peak rewards preparation and punishes complacency. If you're building toward it, spend a season on easier Class 2 peaks first, check the weather and route conditions the day before, and start in the dark. If any of that sounds like more commitment than you're looking for, the park has excellent alpine hikes — like the Bear Lake corridor — that offer big views without the exposure.
