Runner’s can spend years exploring Boulder’s maze of trails, from cruising the paths at Chautauqua Park to climbing the rocky edges of Mt. Sanitas. But a local trail favorite remains the Eagle and Sage trails, which sit to the north of the city near the Boulder Valley Ranch. The trailhead is easily accessible and offers gorgeous views of the Front Range and the Flatirons.
The Eagle and Sage trails offer a smooth, dirt surface that is well maintained and ideal for beginning trail runners. In most spots, the trail is fairly wide and flat. This is the place to go if you’re in the mood for a tempo run or a leisurely run, not if you’re yearning for a lung-burning climb.
There are several small lakes along the well-traveled paths. You’ll encounter prairie dogs, a few horses, as well as cattle grazing on native grasslands as you race through the prairie.
To get to the trailhead, drive north from Boulder or south from Longmont on the Diagonal Highway, Colorado 119. Turn west on Jay Road for about 200 meters, then turn north on 51st Street. You’ll pass the Boulder Reservoir on your right. Keep driving and turn left into the parking lot marked Eagle Trail. You can also access this trail from a different entrance by driving to the Foothills Trailhead parking lot off 28th Street and Route 7.
For an easy 3.7-mile run, start at the Eagle trail parking lot and run along the double track dirt path for a half mile. At the first intersection, turn right to follow the Sage trail. The trail travels a large loop and this section of the Sage trail is 1.8 miles. Each time you meet an intersection, simply choose to turn left. The first intersection will arrive after a half mile. You will come to the second intersection in another 0.6 miles where you will run through the Boulder Valley Ranch Parking lot, veering left. Follow the Sage trail and the Farmer’s Ditch another 0.7 miles until you reconnect with the Eagle trail. Here you will turn left to continue the circle for another 0.9 miles. You’ll pass a beautiful, small lake that’s a popular swimming spot for dogs. Climb a short, steep hill to return to the original intersection of the Eagle/Sage trails. Turn right to follow the trail back to the parking lot for a 0.5 mile finale.
It’s easy to add onto this basic loop for a 6-mile run. Start at the Eagle trail parking lot and follow the directions described above until you reach the Boulder Valley Ranch parking lot. Here you will make a right turn onto the Cobalt Trail. This single track is more technical, so make sure to watch your footing. Once you crest the hill, you will cross over the dirt road and turn left onto the Mesa Reservoir Trail. You will dip down into a valley and come upon a trail crossing. Turn left here, run past the wetlands surrounding the Mesa Reservoir and follow this up to the Eagle Trail and make a right. As you run along this flat section you will be treated to a great view of the Boulder Reservoir off in the distance. Follow the Eagle Trail down a short, steep hill where you will intersect with the Sage Trail. Continue straight along the Eagle Trail and follow the above directions back to the start.
These are just two of the countless options available in the area. There are many more interconnecting trails worth exploring during your runs. This area is great for year-round trail use, although be prepared during inclement weather because the area is exposed to Boulder’s infamous roaring winds and summertime thunderstorms.