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.
Centennial 13er · East Ridge
Overview
Grizzly Peak A is the highest 13er in Colorado. It falls just short of 14,000 feet, and it feels like a fourteener from the top. It sits on the Continental Divide south of Independence Pass, at the head of several long valleys. The east ridge route starts in McNasser Gulch on the east side of the Divide. It is short in miles but steep, and most of the climb is off-trail on grass, talus and broken rock.
The lower half is a walk up an old mining road and grassy slopes. The upper half is a ridge of talus and loose blocks. Near the top the ridge gets steeper and rougher. You will use your hands in a few spots, and some of the rock moves when you step on it. It suits hikers who have done a few Class 2 peaks and are fine on loose, off-trail ground. There is little exposure, but a fall on the loose upper ridge could still hurt you badly.
Plan on 5 to 7 hours round trip for most parties. You are above treeline for nearly the whole day, and there is no quick way off the upper ridge when a storm arrives. The high summit also catches wind and weather early. Start early and treat the ridge as the place you do not want to be at noon.
Plan of the day
Start by
By 5 a.m. You are above treeline almost from the start, and summer storms on the Divide often build by late morning.
Turnaround
If you are not on the east ridge by 10 a.m., or on the summit by 11 a.m., turn around. Head down at once if you see building clouds or hear thunder.
Crux
The last few hundred feet of the east ridge. It steepens into loose blocks and broken rock where you may need your hands and must test every hold.
Route-finding
The gulch is easy to follow on the old road. Above it there is no real trail. The common mistakes are aiming too far left or right below the ridge and ending up on steep, loose slopes. Pick your line to the ridge while you can still see the whole face.
Water
The creek in McNasser Gulch runs most of the summer. There is no reliable water on the ridge. Fill up low and filter or treat all of it; there is old mining in the area.
McNasser Gulch drains the east side of the Divide into the Lake Creek valley. From Twin Lakes, drive west on Highway 82 toward Independence Pass. The McNasser Gulch road leaves the south side of the highway on the east side of the pass, well below the pass summit. The turnoff is easy to miss, so have it marked on a map or GPS before you go.
The road up the gulch is rough and rocky. A high-clearance four-wheel-drive vehicle is needed to drive very far up it. Many people park near the highway or at the first good pullout and walk the road. Do not block the road or the highway shoulder. Highway 82 over Independence Pass is closed in winter and usually opens in late May.
TundraRoadTalus and screeRidgeScramblingExposed 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
McNasser Gulch trailhead 11,200' · 0 mi
Start on the old mining road that heads south up McNasser Gulch. The road climbs at a steady grade through thinning trees and willows, with the creek below you. The valley opens up fast, and you will soon see the high ridges of the Divide at its head.
2
Treeline in the gulch 11,500' · 0.5 mi
The last trees fall behind and the road crosses open meadows. Look for old mine ruins, rusted metal and tailings piles along the way. Stay on the road; the willows off to the sides are thick and wet.
Watch for: Old mine openings and loose tailings. Stay out of them.
3
Road fades 11,800' · 0.9 mi
The road gets fainter and splits into rougher tracks. Keep heading up the main valley toward its head. Grizzly Peak is the big dark summit ahead and to the right, with its east ridge running down toward you.
4
Upper gulch 12,200' · 1.2 mi
Leave the road and trail here and start across the grassy upper basin. Aim for the low point on the ridge east of Grizzly. The grass is broken by small rock bands and patches of talus. Take a good look at the slope above and pick the easiest grassy line up to the saddle.
Watch for: Early season snow may still fill the upper basin. Kick steps or go around it.
5
Slopes below the saddle 12,600' · 1.6 mi
The grass thins and the slope steepens. Climb on a mix of tundra, scree and embedded rock. Zig-zag to take the grade. Stay on the most solid ground you can find and avoid loose gullies.
Watch for: Loose scree. Watch out for people below you and do not kick rocks down.
6
Saddle east of Grizzly 12,900' · 1.9 mi
You reach the crest of the ridge at a broad saddle. The view opens to the south and west. Turn right and look up the ridge toward the summit. This is a good place to check the sky and your time before the rocky part.
Watch for: Wind is often strong here. Put on a layer before you start up the ridge.
7
East ridge 13,200' · 2.2 mi
Follow the ridge west. The ground is talus and broken rock with a faint path in places. Stay near the crest, where the rock tends to be more solid than on the side slopes. Small cairns may mark the way but do not count on them.
8
Mid ridge 13,500' · 2.5 mi
The ridge narrows and gets rockier. You will step up over blocks and around small rock steps. When a step looks hard, look a short way to either side for an easier bypass.
Watch for: Some blocks are loose. Test holds before you pull on them.
9
Steep upper ridge 13,800' · 2.8 mi
The last section is the steepest. The ridge turns into broken, loose rock and you may need your hands. Move slowly and keep three points of contact on the rough spots. Keep parties close together so a dislodged rock cannot gain speed before it reaches the next person.
Watch for: This is the crux. Rockfall and slips are the main dangers here.
10
Summit 13,997' · 3 mi
The ridge ends at a small, rocky summit. You can see across the Sawatch and Elk ranges, down to Grizzly Reservoir to the west, and along the Divide to Garfield Peak to the south. Rest briefly, then start down the same ridge.
Watch for: Do not linger if clouds are building. You have a long exposed ridge to descend.
Landmarks to know
Old mining road heading south up McNasser Gulch from the highway
Mine ruins, rusted metal and tailings piles near treeline
Grizzly Peak as the big dark summit at the head of the valley, east ridge dropping toward you
The broad grassy saddle on the ridge east of Grizzly
Talus ridge running west from the saddle, narrowing as it climbs
Steep band of loose broken rock just below the top
Small rocky summit with Garfield Peak to the south along the Divide
Getting down
Go down the way you came. Take the upper ridge slowly; loose rock is harder to manage going down, and most slips happen here on the way back. Face in on the steepest steps if it helps.
The easiest place to go wrong is leaving the ridge too early. Stay on the crest until you reach the broad saddle east of the summit, then drop into the upper gulch on the grassy line you came up. Cutting down too soon can put you on steep, loose slopes above small cliffs. Once in the basin, head down-valley to find the old road again and follow it back to your car.
If things go wrong
The saddle east of Grizzly is your main decision point. If weather is building or someone is struggling there, go back down to the gulch instead of starting up the ridge. Once you are on the ridge, the fastest way to safety is back down it to the saddle and into the grassy basin. Do not try to drop straight off the upper ridge into unknown gullies. If lightning is close, get off the crest, stay away from tall points, spread your group out and crouch on your pack until it passes. If someone is hurt, keep them warm and still, and send someone down the gulch toward the highway if there is no signal. Call 911 when you can reach help.
3D flyover
Press play to fly the East Ridge. The graph shows elevation along the way and how much you gain each mile. Open full screen.
For planning only. The line is traced from open map data, not walked in the field, and off-trail parts are drawn straight. Load it in your GPS app to see the route, but navigate with your eyes, a map and the route description.
See the trail on video
A climb of this route filmed by Hiking in Colorado. The video belongs to them and only plays when you press play.
Jump to
Other routes
Every way up Grizzly Peak A we list, with its class.
This describes the route on a dry summer day. Snow, ice, a washed-out road or an afternoon storm can make it a very different climb. Check recent conditions the week you go and turn around when the day tells you to.