Walter Orr Roberts Nature Trail is a 0.4 mile loop trail located near Boulder, CO and is good for all skill levels. The trail is primarily used for hiking and is accessible from April until October. 0.4 miles 74 feet Loop hiking Hide Map AllTrails Terrain Road Satellite Expand Map Sign up now to see this map! Reviews (1)Photos (1)Tracks (2)Medha Vora1 year ago82 Completed70 ReviewsReally easy trail, not much of a hike from NCAR. Ok views of Flatirons. Was my 1st hike on moving to Boulder Aug 2014. Went on to MESA trail from there.