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Very popular and scenic loop right from the edge of town.


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Map Key

3.2

Miles

5.2

KM

61%

Runnable

6,780' 2,067 m

High

5,521' 1,683 m

Low

1,281' 390 m

Up

1,280' 390 m

Down

15%

Avg Grade (9°)

43%

Max Grade (23°)

Dogs Off-leash

Features Views

Overview

This is a steep but rewarding trail, with great summit views of the foothils to the high peaks, and all of Boulder. It is virtually always crowded with all kinds of runners, hikers, and dogs.

Need to Know

In typical Boulder fashion, there are some crazy speed records on the various trails.

Runner Notes

Many large steps and off-camber rocks make you keep an eye right ahead of your feet.

Description

From the beginning of the Sanitas Valley Trail, take your first left on the Mount Sanitas Trail and immediately start the very steep ascent of the mountain. The trail is mostly shaded, but there are tons of high steps, both on logs and boulders, which make the trail tiring. You'll pass some large rock outcroppings that are popular with climbers and boulderers and several nice places to rest and enjoy the views both east and west.

After several false summits, you finally gain the true summit and have unobstructed views of all of Boulder to the east, and partially obstructed views of foothills and Indian Peaks to the west.

Head down the very steep East Ridge Trail, which has several tricky sections of steep rock. It eases up as you descend, and finally widens and becomes much easier as you get to a saddle and intersection with the Sanitas Valley Trail.

As you descend this nice, easy gravel road, enjoy the spectacular views of the Flatirons, seen from a unique side-on angle. You'll pass the historic Silver Lake ditch (which supplies water to Boulder farmers and has been in use since the late 1800's) and soon end back where you started.

Flora & Fauna

Mountain lions are common in the area, and the trail is occasionally closed if there is a fresh kill. You'd be lucky to see one though!

History & Background

The peak is named for the Boulder Sanitarium that sat at the current site of the Boulder Community Hospital. The building was completed in 1896 and was primarily used to treat tuberculosis patients. The original smokestack still stands.

There is also an old quarry halfway up the slope (a spur trail will lead you there) that was used for several early University of Colorado buildings.

Contacts

Shared By:

Nick Wilder

Trail Ratings

  4.1 from 127 votes

#104

Overall
  4.1 from 127 votes
5 Star
36%
4 Star
45%
3 Star
16%
2 Star
3%
1 Star
0%
Recommended Route Rankings

#31

in Colorado

#104

Overall
126 Views Last Month
24,487 Since Nov 15, 2014
Intermediate/Difficult Intermediate/Difficult

0%
1%
32%
14%
53%
0%

Photos

Sunrise from Mt Sanitas
Nov 3, 2017 near Boulder, CO
The top of Mount Sanitas looks out at the beauty of Boulder and the Flatirons.
Apr 12, 2017 near Boulder, CO
Sunshine Canyon
Jan 7, 2024 near Boulder, CO
Arriving at the summit, just missed the sunrise.
Dec 2, 2018 near Boulder, CO
Looking east from the summit at sunrise.
Dec 2, 2018 near Boulder, CO
On the descent at 6:30 a.m.
Jul 17, 2019 near Boulder, CO

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Check-Ins

Feb 27, 2023
Trent Hillier
Oct 21, 2022
Trevor Edie
Still good. 3.2mi
Aug 17, 2022
Paula Alvarez de Neyra
Jun 14, 2022
Trevor Edie
Pretty tough rocks, gotta watch your step. 3.2mi
Jun 11, 2022
John Mah
Sep 4, 2021
Tyler
Aug 28, 2021
Kaylee M
Jun 10, 2021
Jessica Montenieri
Lovely and rude if it's your first day at elevation with no sleep — 1h 40m
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