Mount Sanitas: 3 Routes to an Iconic Boulder Peak

Mount Sanitas Summit in Boulder, Colorado

Located right outside Boulder, Mount Sanitas has everything you could want in a convenient hike. It’s a little challenging, has great views, and if you’re lucky—some wildlife (but definitely a dog or twenty). With three distinct routes to the summit, it’s the kind of hike you can do again and again without it getting old.

Trail Info

Trailhead Name	Lion's Lair / Sanitas Ridge/ Sanitas Valley + East Ridge
Distance to summit (one way)	*Lion's Lair:* 2 miles / 3.6 km *Sanitas Ridge:* 1.3 miles / 2.1 km *Sanitas Valley/East Ridge:* 1.9 miles / 3.1 km
Estimated time	2-3 hours (all routes)
Elevation gain	*Lion's Lair:* 800 feet / 244 m *Sanitas Ridge:* 1,250 feet / 380 m *Sanitas Valley/East Ridge:* 1,250 feet / 380 m
Highest point	6,821 ft / 2,079 m (Mount Sanitas)
Permits / fees	None
Parking	*Lion's Lair:* Pull-off along the highway Sanitas Ridge, Valley: Paved lot
Toilets?	*Lion's Lair: None Sanitas Ridge, Valley*: Pit toilet at parking lot
Dog friendly?	*Lion's Lair: No (prohibited) Sanitas Ridge, Valley*: Yes

Know before you go

This is a very popular hike. Both Mount Sanitas and the nearby Flatirons get tons of foot traffic, especially because they’re so close to Boulder. Try going midweek or early in the morning to avoid the crowds.
Parking lots can fill up fast, especially on weekends. Arrive early or be ready to scout for street parking. Just be mindful of posted signs if you're parking in a neighborhood.
The trail is open year-round, but winter conditions can bring snow and ice. Check the forecast and trail reports, and consider tossing microspikes in your pack if you're hiking during colder months.

Which route should I choose?

Beyond distance, gain, and dog policy, here are a few other things to consider:

Sanitas Ridge to Valley Loop is the classic route. It lets you do the steeper section uphill and take a more mellow trail back down.
Lion’s Lair is the gentlest option. It’s a peaceful, forested trail with consistent switchbacks and smoother footing. There's less gain and no scrambling.
Sanitas Valley + East Ridge has extra access points if you’re looking to shorten your hike. You'll park in residential areas, so watch for signage and restrictions.

Sanitas Ridge

After (hopefully) scoring a spot in the Centennial Lot, you’ll cross the highway and hit your first junction. This is where you decide whether to head up Sanitas Ridge or Sanitas Valley.

Sanitas Ridge starts with some big “stairs” that’ll get your heart rate up fast.

There are plenty of lookout spots along the way—great places to catch your breath and soak in the views. That trail you’re seeing in the distance? That’s Sanitas Valley Trail.

One of the best parts of this route is how open it is. You’ll get sweeping views almost the entire way. Turn around and you’ll see the Flatirons, home to some of Boulder’s most famous hikes and climbs.

Look the other direction and you’ll spot the (often) snowcapped Front Range. On a clear day, you can see peaks that top 12,000 and even 13,000 feet.

The final push to the summit is short but steep. Views waiting at the top.

Sanitas Valley / East Ridge

Lion's Lair

The Summit

SS Reflections

I love hikes that feel like a “choose your own adventure. ”Mount Sanitas checks that box perfectly. It’s not alpine, it’s not remote, and yeah, you won’t be alone up there. But when it’s this close, this scenic, and this flexible, it’s hard not to love it.

Other Helpful Resources

This Boulder County website which will reports the status of these trails