I recently completed the hike to Mills Lake, and I can say without a doubt it is one of the most rewarding experiences in Rocky Mountain National Park. We started at the Glacier Gorge Trailhead, which is a great jumping-off point, though I highly recommend getting there early since that lot fills up almost instantly.
I'd describe the difficulty as moderate. The round trip is about 5.4 miles with an elevation gain of roughly 750 feet. It's a steady climb that gets your heart pumping, but it's very manageable for anyone who hikes semi-regularly. One of the highlights for me was passing Alberta Falls about 0.8 miles in, it's a powerful, stunning waterfall that makes for a perfect first break. After the falls, the trail opens up with some expansive views of the gorge before you reach the final junction toward the lake.
When I finally crested the last ridge and saw Mills Lake, I was absolutely stunned. The beauty is hard to put into words. The lake is crystal clear and sits right at the base of the dramatic Keyboard of the Winds and Pagoda Mountain. I spent a long time just sitting on the large, flat "Glacier Ribbon" rocks along the shore, watching the reflection of the jagged peaks in the water. read more