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.
Alternate route · Southeast Slopes
Overview
This route climbs Pacific Peak from McCullough Gulch by way of a high, rocky basin and a steep headwall. Most of the lower half follows a good trail past a lake. Above that you are on faint paths, talus and loose slopes, then a ridge walk to the top. It is rated difficult Class 2, so expect to use your hands in places.
It suits hikers who are comfortable on rough, loose rock and can pick a line without a trail. The headwall at the back of the basin is the hard part. Early in the season it holds snow, and then it becomes a snow climb that needs an ice axe and crampons.
The round trip is about 7.75 miles with about 3,000 feet of gain. Plan on 6 to 9 hours. You can add nearby Atlantic Peak for a little extra distance.
Plan of the day
Start by
By 5 or 6 a.m. The upper basin and ridge are fully exposed, and summer storms often build by late morning.
Turnaround
If you are not at the top of the headwall near 13,200 feet by about 10:30 a.m., or clouds are building, turn around.
Crux
The loose headwall between roughly 12,800 and 13,200 feet, where the upper basin ends to the northwest. Pick the easiest line in the middle.
Route-finding
Moderate. The trail is clear to the first lake, then fades. Above 12,400 feet you pick your own way across talus and up the headwall to the Atlantic-Pacific ridge.
Water
Creeks and lakes in the lower gulch. Filter anything you drink. Carry at least 2 to 3 liters for the upper route.
Head south out of Breckenridge on Colorado 9 for roughly 8 miles. Make a right onto the Blue Lakes road (850), and shortly after, another right puts you on the McCullough Gulch road (851). After roughly 1.4 miles there is a small lot on your left; this is where the summer shuttle loops back.
Leave the lot on foot and keep going up the road for roughly 0.3 mile, beyond a gate. Signs point the way to the McCullough Gulch trail. Parking is limited, so arrive early or use the shuttle when it runs.
Talus and screeTundraRidgeExposed 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
McCullough Gulch trailhead 11,000' · 0 mi
Walk past the gate and follow the road as it bends up to the left. The grade is gentle.
2
Leave the road for the trail 11,100' · 0.5 mi
About half a mile in, a signed trail leaves the road. Take it into the forest. You cross a few small log bridges and a boulder field.
3
Trail split near 11,600 feet 11,600' · 1.4 mi
Keep right where the trail splits. Climb a rocky rise toward the first lake.
Watch for: Keep right here. Other paths lead elsewhere in the gulch.
4
Unnamed lake 12,000' · 2 mi
Reach a lake at about 12,000 feet. Skirt it on the right, then take the trail as it climbs a rocky slope.
5
Rib below Fletcher and Atlantic 12,400' · 2.4 mi
Climb to about 12,400 feet, just south of a rock rib that runs east to west across the basin. Once in the upper basin, pick up a faint path heading west in the direction of Atlantic Peak.
6
Small lake at 12,555 feet 12,555' · 2.8 mi
Beside a small lake, on its north side, swing right and go north. Cross about half a mile of rough talus to the foot of the headwall at the northwest corner of the basin.
Watch for: Talus here can shift. Test each step.
7
Base of the headwall 12,800' · 3.3 mi
Look for the easiest line near the middle of the slope and climb the loose ground. Near the top, angle left onto easier terrain.
Watch for: This is the crux. Watch for rockfall from people above. If it is snow covered, use an ice axe and crampons.
8
Top of the headwall 13,200' · 3.5 mi
The ground eases. Hike northwest toward the ridge that links Atlantic and Pacific.
9
Atlantic-Pacific ridge 13,400' · 3.7 mi
Aim a little right of the low point and climb to the crest. Atlantic Peak is to the south if you want to add it.
10
Point near 13,500 feet 13,500' · 3.8 mi
Walk north along the ridge. Go around a small bump rather than over it, then follow Pacific's south ridge up.
11
Summit of Pacific Peak 13,965' · 3.9 mi
Reach the top. The summit is small and rocky with big views of the Tenmile Range.
Getting down
Return the way you came. Take extra care going down the headwall, which is loose and easy to knock rocks off. Once back in the basin, retrace your line across the talus to the small lake, then pick up the trail past the first lake and back to the road. To add Atlantic Peak, leave the ridge near 13,400 feet and walk south, then come back to the route. It adds about three quarters of a mile.
If things go wrong
The quickest way out from the ridge is back down the headwall into the basin. Below the headwall there is no shelter until you drop toward the lakes and trees, so leave early if weather builds. If someone is hurt on the talus or headwall, move them to stable ground, keep them warm and call 911 if you have signal. Rescue in this basin can take many hours.
Other routes
Every way up Pacific Peak we list, with its class.
This describes the route in its usual season. Distances and elevations are close estimates for planning. Snow, ice, rockfall, 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.