Hike McCullough Gulch to Upper Blue Reservoir



2.8 miles

Elevation Gain

910 ft

Route Type


Added by The Outbound Collective

With peaks, lakes, and waterfalls, this trail is steep in parts, but always scenic and worth the push.

The trail first takes you to Upper Blue Reservoir, about 1.4 miles in. Past this point, it can be somewhat tricky to find the trail, but for experienced hikers, the upper valley holds a number of lakes, a waterfall, and open tundra for exploring. Mountain goat sightings are also common in this area, so keep an eye out!

Read More

Know for

Dog Friendly



Leave a Review

Wrong name of lake

Beautiful hike, but this lake is not actually called Upper Blue Reservoir, and at this time has no official name. There was an error in the US Geographic Names Information System (GNIS), which incorrectly put Upper Blue Reservoir on the north flank of Quandary Peak, south of this lake. This reservoir is actually in Monte Cristo gulch south of Quandary. I reported the error, and the coordinates have since been fixed. See https://geonames.usgs.gov/apex/f?p=138:3:::NO:3:P3_FID,P3_TITLE:199759,Upper%20Blue%20Lake


πŸ₯‡Top Contributor

6 months ago

Pretty but strange

Go early. It's amazing the number of people that rock up for the hike between 12-1. I was one of the first cars to show up at around 10 am on a Wednesday but by the time I left, there were about 20 more. A good climb and easy to get to from 9. If you're there early, there's a small carpark, otherwise, you park from the fork, back. Walk on an easy and clear service road, though at this time in October it's icy. Basically stick left. This trail was kinda weird because there were clear trails, but at the same time, not. At that the first trailhead, there's a sign that says waterfall 1 mile and lower blue lake in 1.4 miles. I stuck to the left up the trail, came across an old mining cabin, and kept climbing. Then there was a trail that took a turn down. I wasn't sure if that was too the lower lake, but I kept climbing through the treeline and eventually getting to the base of the waterfall. I read the waterfall is an additional mile that reconnects to the main trail. At the waterfall, I saw a "trail" sign that pointed to the base and walked towards another sign that just had me do a quick loop around. I looked around to find a third "trail" sign going up and continued on. There were some clear indicators of the main trail like footbridges and more signs, but as you climbed around rocks and looking for trails, they kind of threw you around everywhere. Eventually at the top of the waterfall, it'll fork off again. Left going to the end of the lake and the right taking you over the lake. The trail on right will continue on past upper blue lake, but the wind was so strong I decided to turn around and head back down. It was a nice walk, but can't say I'd do it again. I rather give this walk a 3.5 rating.


My first, and favorite, hike I've done in Colorado!

214 total saves


Leave No Trace

Always practice Leave No Trace ethics on your adventures and follow local regulations. Please explore responsibly!

We want to acknowledge and thank the past, present, and future generations of all Native Nations and Indigenous Peoples whose ancestral lands we travel, explore, and play on.

Nearby Adventures

Hike the East Ridge of Pacific Peak

8 mi / 3500 ft gain

Winter Hike to Quandary Peak (14,265')

7 mi / 3500 ft gain

Ski or Snowshoe McCullough Gulch

6 mi / 1300 ft gain

Winter Climb of North Star Mountain

8 mi / 2400 ft gain
More Nearby Adventures