Five Trails for Hill Running and Mountain Training

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As one year comes to a close and another begins, the annual ritual of planning future goals, races, and adventures starts. As one reflects back on their previous year’s accomplishments and races, the desire to improve is almost a universal athletic urge. Whether it is to place higher in a race or run a certain distance faster, the achievement of those goals requires planning and training.

The type of training one undertakes to achieve their goals varies depending on the nature of the sought-after objective – running faster requires one type of specific training while running farther requires another. However, almost every coach and professional athlete would agree that hill running is a necessary part of any successful training program.

In Boulder, where runners are known to run farther, train harder, and push the limits of conventional training wisdom, there are five prominent hill and mountain runs that people look to in improving their fitness and working towards achieving their goals. Forming the western skyline from north to south they are: Mount Sanitas, Green Mountain, Bear Peak, South Boulder Peak, and the granddaddy of them all, the famous Skyline Traverse, which runs over all of the peaks forming one ultra-long mountain workout. Incorporating one or all of these hill and mountain runs into your regular training regime will not only boost your ego, but also make you a stronger, fitter runner.

Mount Sanitas Hill Climb

Trip Time: 15-30 minutes (for the one way); 20-50 minutes (for the out-and-back)
Round-Trip Distance: 2.54 miles
Total Elevation Gain: 1,352 feet (one way)


The Summit of Mount Sanitas offers spectacular views of the town below. Photo: Todd Straka

Getting There

The Sanitas trailhead is located just west of 4th street on Mapleton Avenue. Look for parking on the right (north) just past the Boulder Community Hospital Mapleton Center.

The Run

The run to the top of Mount Sanitas may be short, but it is steep, maintaining an average grade of 19%. From the Sanitas trailhead, the trail immediately branches to the left (the right enters Sanitas Valley) after crossing a small stream and begins the steep climb to the summit. The trail hugs the backside of the ridge initially, passing several local climbing areas as you work your way up a series of stair-steps past sandstone rock formations before the trail mellows out and you cross over onto the frontside of the ridge. Here you are greeted with your first view of the Sanitas Valley and the city of Boulder to the east. Continue climbing up the steep and rocky trail over another series of stair steps, after which the trail eases up and stays more directly on the ridge proper, before beginning the final short climb up a few switchbacks to the summit. From the summit of Mount Sanitas enjoy the views in all directions, with Boulder and the Plains to the east and the Continental Divide to the west. For the out-and-back, turn around and retrace your steps. Alternatively, you can descend down the steep East Ridge trail through interesting rock formations and rocky switchbacks to Sanitas Valley. From here the East Ridge trail ends and you can run down the valley’s wide gravel road for a nice loop.

Green Mountain Hill Climb

Round-Trip Time: 1-3 hours
Round-Trip Distance: 6.47 miles
Total Elevation Gain: 2,288 feet

5Trails_Bear Peak

From the peak of Green Mountain, one can navigate the peaks along the Continental divide in the distance and more. Photo: Peter Jones

Getting There

The trails going up Green Mountain can be accessed from the Chautauqua trailhead, which is located off of Baseline road and 9th street. From Chautauqua, head west through the large meadow on the trail that parallels Baseline Road before dropping down to Gregory Canyon, where the real climbing begins.

The Run

From the parking lot at the base of Gregory Canyon, continue on the Gregory Canyon trail as you parallel a small seasonal stream, passing the turnoff to Saddle Rock (on the left), and climbing along rocky terrain. Although the Gregory Canyon trail is only 1.18 miles, it gains over 1,000’ making for a very hard effort. After some switchbacks, the trail has a small downhill section that allows for a quick recovery. Shortly after, the trail merges with the Ranger trail and passes by the old Green Mountain Lodge. Here the trail enters a dense section of forest before branching again – the E.M. Greenman trail heads left, while the Ranger trail continues to the right. Continue to the right on the Ranger trail as you climb through alternating sections of soft pine needle covered trail and rocky stair step trail. Before the final summit push, the trail arrives at a junction; turn left (east) onto the Green Mountain West Ridge trail for the final couple hundred feet of climbing before reaching the summit and enjoying the well deserved 360 degree views.

If you want to make the run a loop, you can come down the “frontside.” From the top of Green Mountain, head down the E.M. Greenman trail until you reach the junction with the Saddle Rock trail. Turn onto Saddle Rock (right) and continue down to the junction with the Amphitheater trail, staying right and continuing down the steep, rocky Amphitheater trail until you are at the base of the canyon. From here, you can follow the trail that parallels Baseline Road back to Chautauqua Park.

Bear Peak via Bear Canyon

Round-Trip Time: 1½-4 hours
Round-Trip Distance: 10.9 miles
Total Elevation Gain: 2,752 feet


View of Green Mountain from Bear Peak. Photo: Peter Jones

Getting There

The NCAR trailhead, located at the National Center for Atmospheric Research, can be accessed from the west end of Table Mesa Drive. Follow Table Mesa Drive west until it turns into NCAR Road. Follow NCAR Road up onto the mesa and park in the large parking lot. The trails are well marked with signs and maps, and are located just west of the parking lot.

The Run

From the parking lot at NCAR, begin by running west on the Walter Orr Roberts trail (an interpretive trail). The trail heads west on a small mesa before dropping to a saddle, and then ascending again to a water tank. Shortly after the trail branches; take the southern branch to its junction with the Mesa Trail. Turn left (south) onto the Mesa Trail and continue down to Bear Canyon proper, at which point the trail merges with a gravel road. From here the trail begins a quick but steep climb as you follow the road past one switchback to the turn off onto the Bear Canyon trail. Turn onto the Bear Canyon trail (west) and follow it into Bear Canyon. After you have run through the canyon, the trail passes through several small meadows as it continues to climb before splitting again at the Bear Peak West Ridge and Green Bear trails. Turn onto the Bear Peak West Ridge (left) and follow this trail as you begin the long climb up Bear Peak’s west ridge, passing through a large burn zone that was formerly rolling ponderosa forests and rocky ridgelines. The Bear Peak West Ridge starts out with a mellow grade, but quickly becomes very steep as you gain 1,400 feet in under 2 miles. Finally, after climbing several rocky, stair-step switchbacks, the trail merges with the Bear Peak trail. Turn left (east) and make the final climb to the summit of Bear Peak along a rocky ridgeline. From the top enjoy spectacular views in all directions, as well as a little exposure while resting on the summit. When you are ready, turn around the follow your tracks back to the car over 2,700 feet below.

If you want to make the run into a loop, from the summit of Bear Peak head north and east down the Fern Canyon trail for a very steep, rocky 1.06 miles. Shortly after emerging from the cool, shaded Fern Canyon the trail splits; take the left (north) trail until it drops you onto a gravel road. Continue down (left) this gravel road until you reach the Bear Canyon trail junction. From here, retrace your steps back up to the NCAR parking lot using the same trails as you did at the beginning.

South Boulder Peak via Shadow Canyon

Round-Trip Time: 1½-3½ hours
Round-Trip Distance: 7.52 miles
Total Elevation Gain: 2,920 feet

The view to the South of South Boulder Peak

The view to the South of South Boulder Peak. Photo: Todd Straka

Getting There

The South Mesa trailhead can be accessed from Eldorado Springs Drive, located just outside of Boulder. Turn onto Eldorado Springs Drive from Highway 93/S. Broadway and follow it for approximately 0.8 miles. The trailhead and parking are on the right (north), directly across from the Doudy Draw trailhead parking. The trail starts from the parking lot and is well marked with signs and maps.

The Run

From the parking lot at the South Mesa trailhead begin by running on the Mesa trail to an old cabin (the historic Dunn house built in 1875) located shortly after crossing South Boulder creek. Turn west (left) here and run up the Towhee trail as you gently climb up a small wash through open meadows to the top of the mesa. Near the top the Towhee trail rejoins the Mesa trail, which at this point is a gravel road. Turn left, staying west on the Mesa trail and follow it as it continues to wind through open grasslands before the Mesa trail splits; going right (north) keeps you on the Mesa trail, while staying left puts you onto the beginning of the Shadow Canyon trail. Follow the Shadow Canyon trail, which at this point is still a gravel road, as you briefly descend before climbing again. On your left you will pass by the historic McGilvery Cabin, which was built in the 1870s. After a steep section of climbing up some switchbacks, the gravel road peters out and the trail enters the cool shade of the forest before reaching Shadow Canyon proper and the historic Stockton Cabin built in 1910. At this point the trail enters the cool, shaded canyon as it quickly steepens passing by tall rock formations on either side. This is the steepest part of the run, as the trail gains 1,600 feet in only 1.22 miles. After climbing, the trail reaches the saddle between South Boulder Peak and Bear Peak. From here, the trail turns west (left) as it climbs the final bit to the summit through a large forest fire burn zone. From the top enjoy the spectacular views in all directions, including down into Eldorado Canyon. When you are ready, turn around the follow your tracks back to the car over 2,900 feet below.

The Skyline Traverse

Trip Time: 3½ – 5 hours
Trip Distance: 15.91 miles (one way), 24.55 (round trip)
Total Elevation Gain: 6,354 feet (one way); 8,115 feet (round trip)

View to the south from Bear Peak

View to the south from Bear Peak. Photo Todd Straka

Getting There

This traverse can be done by either starting at the South Mesa trailhead (on the south end of the traverse) or the Sanitas trailhead (on the north end of the traverse). The description here runs south to north and begins at the South Mesa trailhead. See above for directions to the South Mesa trailhead.

The Run

The first half of this classic traverse follows the trails leading up to South Boulder Peak described above. From the summit of South Boulder Peak return to the saddle where Shadow Canyon meets up with the South Boulder Peak trail and the Bear Peak trail. Run past the Shadow Canyon trail and head over to Bear Peak alongside the peak’s rocky western flanks. Soon the trail meets a junction with Bear Peak’s West Ridge trail and the Fern Canyon trail. Run the final couple hundred feet to the summit of Bear Peak, and then turn around and begin descending down the West Ridge trail as described above. Continue down the West Ridge trail until reaching the junction with the Bear Canyon and Green Bear trails right after crossing Bear Creek itself. Turn left (north) onto the Green Bear trail and begin the meandering climb up the southwest slopes of Green Mountain. After 1.48 miles the Green Bear trail reaches the junction with the Green Mountain West Ridge trail. Turn right (east) and continue climbing, passing the turnoff for the Ranger trail, reaching the summit of Green Mountain.

From the summit of Green Mountain, turn around and follow your steps back to the Ranger trail. Run down the fast and fun Ranger trail until reaching the old Green Mountain Lodge. Continue down the trail, which at this point turns into double track and follow it for 0.15 miles until a junction; keep left and briefly climb up to a parking lot and Flagstaff Mountain road.

Cross over Flagstaff Mountain road and run on the Ute trail, which gently ascends and meanders over and past the non-descript summit of Flagstaff Mountain (the trail does not actually reach the true summit, which is located in the trees just north of the trail’s high point). Near the top the Ute trail reaches a four-way junction; turn right and begin the descent down Flagstaff Mountain trail, crossing Flagstaff road 5 times. Shortly after crossing the road for the 5th time, the trail reaches an unmarked junction in a small meadow; take the left (north) junction as it turns and parallels Flagstaff road. Cross Flagstaff road once again, and immediately after turn left (north) onto the Panorama trail just beyond the popular tourist overlook. Follow the Panorama trail across the open meadow, cross Flagstaff road one final time, and turn onto the Viewpoint trail. Run down the Viewpoint trail as it rapidly descends down the north slopes of Flagstaff Mountain towards Boulder Creek.

The Viewpoint trail ends at a gate; continue past the gate and down the alley to the roundabout on Arapahoe Ave. Cross Arapahoe Ave. and drop down into Eben G. Fine Park along Boulder Creek (there is potable water available in the park). Turn and run up (west) Eben G. Fine Park on the Boulder Creek path; at the end of the park, cross over Boulder Creek on the bridge and continue on the path until reaching Settlers’ Park. From Setters’ Park, run on the Red Rocks trail up and over the small hump that is Red Rocks and back down to the Mount Sanitas trailhead on the other side of Sunshine Canyon Dr. From here, the final leg of the traverse is climbing up Mount Sanitas and back, as described above.

To make this run a loop, follow your steps back over Red Rocks, through Eben G. Fine park, to Arapahoe Ave. Run east on Arapahoe Ave. until reaching 7th St. Turn right (south) and begin the mellow climb along 7th St. until reaching Chautauqua Park at the intersection with Baseline Rd. Run across Baseline Rd. and hop onto the trail heading east towards the park. From here, run the Mesa Trail all the way back to the South Mesa trailhead. Completing the loop as described adds 8.64 miles for a total round trip of 24.55 miles.

The Best Front Range Trail Runs by Peter N. Jones



These runs and trail descriptions were adapted from the book The Best Front Range Trail Runs (CMC Press 2014), by Peter Jones, which contains 50 trail runs along the Front Range of Colorado. The book can be purchased at Trident Book Sellers or on the Colorado Mountain Club website.

Running Trails Boulder, CO

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