Benjamin Trail Loop — Betasso Preserve

Up to 2 hours and 1,000 ft. of elevation gain. Great for any fitness level.Easily-accessible paths. Suitable for all skill levels.
Corresponds approx.to SAC 1.

Up to 5 hours and 3,000 ft. of elevation gain. Requires good fitness.Mostly accessible paths. Sure-footedness required.
Corresponds approx. to SAC 2-3.

More than 5 hours long or 3000 ft. of elevation gain. Requires very good fitness.Sure-footedness, sturdy shoes and alpine experience required.
Corresponds approx. to SAC 4–6.

Technical difficulty rating based on the Swiss Alpine Club (SAC) Hiking Scale.

Moderate

4.8

465

Chautauqua Trail & Royal Arch Trail loop — Boulder Open Space & Mountain Parks

02:27h

6.70km

410m

How to understand each route’s difficulty level

Hiking

Bike

Mountain Bike

Road Bike

Running

Up to 2 hours and 1,000 ft. of elevation gain. Great for any fitness level.Easily-accessible paths. Suitable for all skill levels.
Corresponds approx.to SAC 1.

Up to 5 hours and 3,000 ft. of elevation gain. Requires good fitness.Mostly accessible paths. Sure-footedness required.
Corresponds approx. to SAC 2-3.

More than 5 hours long or 3000 ft. of elevation gain. Requires very good fitness.Sure-footedness, sturdy shoes and alpine experience required.
Corresponds approx. to SAC 4–6.

Technical difficulty rating based on the Swiss Alpine Club (SAC) Hiking Scale.

Moderate

4.8

422

Mount Sanitas Loop — Boulder Open Spaces & Mountains Parks

02:34h

6.33km

440m

How to understand each route’s difficulty level

Hiking

Bike

Mountain Bike

Road Bike

Running

Up to 2 hours and 1,000 ft. of elevation gain. Great for any fitness level.Easily-accessible paths. Suitable for all skill levels.
Corresponds approx.to SAC 1.

Up to 5 hours and 3,000 ft. of elevation gain. Requires good fitness.Mostly accessible paths. Sure-footedness required.
Corresponds approx. to SAC 2-3.

More than 5 hours long or 3000 ft. of elevation gain. Requires very good fitness.Sure-footedness, sturdy shoes and alpine experience required.
Corresponds approx. to SAC 4–6.

Technical difficulty rating based on the Swiss Alpine Club (SAC) Hiking Scale.

Moderate

4.8

427

First & Second Flatiron — Boulder Open Space & Mountain Parks

01:52h

4.41km

390m

How to understand each route’s difficulty level

Hiking

Bike

Mountain Bike

Road Bike

Running

Up to 2 hours and 1,000 ft. of elevation gain. Great for any fitness level.Easily-accessible paths. Suitable for all skill levels.
Corresponds approx.to SAC 1.

Up to 5 hours and 3,000 ft. of elevation gain. Requires good fitness.Mostly accessible paths. Sure-footedness required.
Corresponds approx. to SAC 2-3.

More than 5 hours long or 3000 ft. of elevation gain. Requires very good fitness.Sure-footedness, sturdy shoes and alpine experience required.
Corresponds approx. to SAC 4–6.

Technical difficulty rating based on the Swiss Alpine Club (SAC) Hiking Scale.

Moderate

4.5

378

Royal Arch Trail — Boulder Open Space & Mountain Parks

01:58h

5.46km

340m

How to understand each route’s difficulty level

Hiking

Bike

Mountain Bike

Road Bike

Running

Up to 2 hours and 1,000 ft. of elevation gain. Great for any fitness level.Easily-accessible paths. Suitable for all skill levels.
Corresponds approx.to SAC 1.

Up to 5 hours and 3,000 ft. of elevation gain. Requires good fitness.Mostly accessible paths. Sure-footedness required.
Corresponds approx. to SAC 2-3.

More than 5 hours long or 3000 ft. of elevation gain. Requires very good fitness.Sure-footedness, sturdy shoes and alpine experience required.
Corresponds approx. to SAC 4–6.

Technical difficulty rating based on the Swiss Alpine Club (SAC) Hiking Scale.

Moderate

5.0

265

Rattlesnake Gulch Trail loop — Eldorado Canyon State Park

02:03h

6.13km

300m

How to understand each route’s difficulty level

Hiking

Bike

Mountain Bike

Road Bike

Running

Up to 2 hours and 1,000 ft. of elevation gain. Great for any fitness level.Easily-accessible paths. Suitable for all skill levels.
Corresponds approx.to SAC 1.

Up to 5 hours and 3,000 ft. of elevation gain. Requires good fitness.Mostly accessible paths. Sure-footedness required.
Corresponds approx. to SAC 2-3.

More than 5 hours long or 3000 ft. of elevation gain. Requires very good fitness.Sure-footedness, sturdy shoes and alpine experience required.
Corresponds approx. to SAC 4–6.

Technical difficulty rating based on the Swiss Alpine Club (SAC) Hiking Scale.

Moderate

4.5

247

Anemone Loop Trail — Boulder Open Space & Mountains Parks

02:08h

7.02km

250m

How to understand each route’s difficulty level

Hiking

Bike

Mountain Bike

Road Bike

Running

Up to 2 hours and 1,000 ft. of elevation gain. Great for any fitness level.Easily-accessible paths. Suitable for all skill levels.
Corresponds approx.to SAC 1.

Up to 5 hours and 3,000 ft. of elevation gain. Requires good fitness.Mostly accessible paths. Sure-footedness required.
Corresponds approx. to SAC 2-3.

More than 5 hours long or 3000 ft. of elevation gain. Requires very good fitness.Sure-footedness, sturdy shoes and alpine experience required.
Corresponds approx. to SAC 4–6.

Technical difficulty rating based on the Swiss Alpine Club (SAC) Hiking Scale.

Moderate

4.9

211

Walker Ranch Loop — Eldorado Canyon Park

03:49h

12.7km

430m

How to understand each route’s difficulty level

Hiking

Bike

Mountain Bike

Road Bike

Running

Up to 2 hours and 1,000 ft. of elevation gain. Great for any fitness level.Easily-accessible paths. Suitable for all skill levels.
Corresponds approx.to SAC 1.

Up to 5 hours and 3,000 ft. of elevation gain. Requires good fitness.Mostly accessible paths. Sure-footedness required.
Corresponds approx. to SAC 2-3.

More than 5 hours long or 3000 ft. of elevation gain. Requires very good fitness.Sure-footedness, sturdy shoes and alpine experience required.
Corresponds approx. to SAC 4–6.

Technical difficulty rating based on the Swiss Alpine Club (SAC) Hiking Scale.

Moderate

4.9

189

Lake Isabelle Loop — Indian Peaks Wilderness

02:52h

9.73km

150m

How to understand each route’s difficulty level

Hiking

Bike

Mountain Bike

Road Bike

Running

Up to 2 hours and 1,000 ft. of elevation gain. Great for any fitness level.Easily-accessible paths. Suitable for all skill levels.
Corresponds approx.to SAC 1.

Up to 5 hours and 3,000 ft. of elevation gain. Requires good fitness.Mostly accessible paths. Sure-footedness required.
Corresponds approx. to SAC 2-3.

More than 5 hours long or 3000 ft. of elevation gain. Requires very good fitness.Sure-footedness, sturdy shoes and alpine experience required.
Corresponds approx. to SAC 4–6.

Technical difficulty rating based on the Swiss Alpine Club (SAC) Hiking Scale.

Easy

5.0

214

Green Mountain West Ridge Trail — Boulder Open Space & Mountain Parks

01:56h

6.83km

150m

How to understand each route’s difficulty level

Hiking

Bike

Mountain Bike

Road Bike

Running

Up to 2 hours and 1,000 ft. of elevation gain. Great for any fitness level.Easily-accessible paths. Suitable for all skill levels.
Corresponds approx.to SAC 1.

Up to 5 hours and 3,000 ft. of elevation gain. Requires good fitness.Mostly accessible paths. Sure-footedness required.
Corresponds approx. to SAC 2-3.

More than 5 hours long or 3000 ft. of elevation gain. Requires very good fitness.Sure-footedness, sturdy shoes and alpine experience required.
Corresponds approx. to SAC 4–6.

Technical difficulty rating based on the Swiss Alpine Club (SAC) Hiking Scale.

Moderate

3.0

170

Lost Lake via Devil's Thumb Trail — Roosevelt National Forest

02:03h

5.28km

240m

How to understand each route’s difficulty level

Hiking

Bike

Mountain Bike

Road Bike

Running

Up to 2 hours and 1,000 ft. of elevation gain. Great for any fitness level.Easily-accessible paths. Suitable for all skill levels.
Corresponds approx.to SAC 1.

Up to 5 hours and 3,000 ft. of elevation gain. Requires good fitness.Mostly accessible paths. Sure-footedness required.
Corresponds approx. to SAC 2-3.

More than 5 hours long or 3000 ft. of elevation gain. Requires very good fitness.Sure-footedness, sturdy shoes and alpine experience required.
Corresponds approx. to SAC 4–6.

Technical difficulty rating based on the Swiss Alpine Club (SAC) Hiking Scale.

Hard

5.0

171

3 Crater Lakes — James Peak Wilderness

04:37h

11.1km

570m

How to understand each route’s difficulty level

Hiking

Bike

Mountain Bike

Road Bike

Running

Up to 2 hours and 1,000 ft. of elevation gain. Great for any fitness level.Easily-accessible paths. Suitable for all skill levels.
Corresponds approx.to SAC 1.

Up to 5 hours and 3,000 ft. of elevation gain. Requires good fitness.Mostly accessible paths. Sure-footedness required.
Corresponds approx. to SAC 2-3.