Afternoon storm risk is the line that matters. Everything else is comfort. In summer, plan to be off the ridge before the build-up starts, not as it starts. Forecast for the summit point, adjusted for its elevation · data from Open-Meteo.
Colorado 13er · South Ridge from the Lenawee Trail
Overview
Lenawee Mountain rises above Arapahoe Basin ski area. From the Peru Creek road, the Lenawee Trail climbs through forest above treeline; you leave it near 12,200 feet, reach the south ridge, and follow a rugged ridge over a couple of points to the summit.
It is hard Class 2, and with snow on the ridge you will make some Class 3 moves. The last 0.6 mile has some drop and regain.
The round trip is about 7.75 miles with 3,200 feet of gain.
Plan of the day
Start by
By 7 a.m.
Turnaround
Be at Point 13,100 by 10:30 a.m.
Crux
The last 0.6 mile of rugged ridge.
Route-finding
Moderate. Leave the trail near 12,200 feet and head northeast to the ridge. Near the end, bypass the crest on the left.
From US 6 at the west end of Keystone, take the Montezuma Road about 4.3 miles and turn left into a big parking area at the start of dirt road 260 (Peru Creek).
Drive 1.7 miles on road 260 to the Lenawee trailhead at 10,350 feet. There's room for a car or two by the sign and a few more just up the road.
TundraOff-trail, no set pathRidgeExposed to lightning
The line is elevation, the band underneath is the ground, and the numbered dots match the steps below. Mileage and elevations are approximate.
1
Lenawee trailhead 10,350' · 0 mi
Start northwest into the forest on the marked Lenawee Trail, also used by mountain bikers coming down from A-Basin.
2
Thurman Gulch view 11,500' · 1.3 mi
Cross an avalanche path and climb to a view into Thurman Gulch.
3
Treeline 11,800' · 1.8 mi
Leave the forest with the south ridge in view. The trail heads south, then north above treeline.
4
Leave the trail 12,200' · 2.4 mi
Head northeast across tundra.
5
South ridge 12,600' · 2.8 mi
Reach the crest in less than half a mile.
6
Point 13,100 13,100' · 3.25 mi
Walk north and northwest up the easy ridge. You can skirt the top of the point on its east side.
7
Summit 13,201' · 3.85 mi
Weave down to a low point, go over a distinct point (easier than it looks), and stay on or left of the crest. Near the turn toward the summit, bypass the crest on the left.
Watch for: Class 3 moves if there is snow.
Getting down
Return the same way.
If things go wrong
The Lenawee Trail is below the ridge.
3D flyover
No 3D flyover for this peak
Above 12,200 feet the route follows a trailless ridge. A flyover only works when there is a set trail to trace. Without one, the line would be a guess, and a guess could send you the wrong way on the mountain. Use the step-by-step route with a good map and GPS track instead.
See the trail on video
No video yet
We haven’t found a good video of this route that matches the way we describe it. The route strip, junctions and 3D flyover show the way in the meantime.
Other routes
Every way up Lenawee Mountain we list, with its class.
This describes the route on a dry summer day. Most 13ers see few people, so there may be no one along behind you. Check recent conditions the week you go, carry a map, tell someone your plan, and turn around when the day tells you to.