Flattop Mountain and Hallett Peak Hike

Route Description for Flattop Mountain and Hallett Peak Hike

Flattop Mountain Trail

Don’t let the distance fool you – the Flattop Mountain trail can be challenging. Furthermore, the weather in this part of the Rockies can be variable, and in many cases you’ll experience very different conditions at the summit than you started with at the beginning of the hike. Pay close attention if lightning is forecast, and if so, consider a different hike.It’s also important to be mindful of the time of year. Flattop typically starts to see snow at the end of September. This summit hike will challenge you but not to the extreme of some of the other summit hikes of the park.

To start your hike up to Flattop Mountain, head to the right from the Bear Lake trailhead, going counter-clockwise around Bear Lake. In less than 0.4 km, you’ll see the turn-off for Flattop Mountain. It is marked with a sign and stairs. You’ll see the trailhead billboard just around the corner.

Follow the path for almost a 0.8 km until you reach the first intersection. Hang a left, following the well-marked signs for Flattop Mountain. You’ll travel on a gradual incline through aspens and thick pine trees for another 0.8 km to the next intersection. Here you’re going to turn left again and continue heading up. There are no other intersections until the summit of Flattop.

Approximately 3.2 km in, you’ll come to the corner of a switchback with a sign that says “Dream Lake Overlook. Do not descend.” Get as close to the edge as you feel comfortable and peer down, but be careful! You’ll see Dream Lake down below, amongst the trees.

At 4.4 km into the hike, the trees start to thin and get smaller and smaller. Look to your right, and you’ll see Lake Bierstadt and Sprague Lake down below. If you look behind you, you’ll see Longs Peak towering over the valley.

You’ll be able to look down on Emerald Lake (marked by a sign) approximately 4.8 km into the hike.

Just after looking down on Emerald Lake, the next set of switchbacks lead you out into the open, exposed alpine. The trail becomes rockier but is still well marked by a well-worn path. Keep climbing for another 2.4 km. It is often very windy at this point, making the trail seem more difficult than it is. Look to your left and you’ll see the summit of Hallett Peak. To the right is the Mummy Mountain Range.

The trail eventually levels out and you’ll come to a signpost marking an intersection. This is the summit of Flattop. While you can turn around and head back the way you came, this is a great chance to also summit Hallett Peak.

Hallett Peak Hike

To summit Hallett Peak (note, this route isn’t shown on the GPS), follow the path as it continues straight and slightly to the left (heading south west). It’s another 1.2 km to the summit of Hallett and can be very challenging, often taking up to an hour. The elevation makes this ascent particularly difficult, especially to those who aren’t from Colorado.

From Hallett Peak, you can look down the western side of Rocky Mountain Park. While there are trails visible, none of them will take you back to the trailhead you started at.

To get back to the trailhead, turn around, retracing the way you came.

Want to find more amazing hikes in Rocky Mountain National Park? Check out Chasm Lake hike, Lake Haiyaha hike or the Sky Pond and Lake of Glass hike.