McIntosh Lake loop — Longmont, Colorado

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.

Intermediate

4.8

450

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.

Intermediate

4.8

413

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.

Intermediate

4.8

414

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.

Intermediate

4.5

362

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.

Intermediate

4.5

239

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.

Easy

5.0

210

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.

Intermediate

4.7

135

Lion's Lair & Mount Sanitas Trail loop — Boulder Open Space & Mountain Trails

03:05h

8.94km

400m

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

4.8

153

Mallory Cave Trail — Boulder Open Space & Mountain Parks

01:50h

5.52km

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.

Intermediate

5.0

140

Mount Sanitas Trail — Boulder Open Space & Mountain Trails

01:47h

4.32km

360m

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.

Expert

5.0

111

South Boulder Peak & Bear Peak via Shadow Canyon Trail — Boulder Open Space & Mountain Parks

05:28h

14.3km

900m

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

115

Anne U White Trail — Boulder Open Space & Mountain Parks

01:29h

5.09km

140m

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.