This document provides information about outdoor recreational activities in and around Boulder, Colorado, including biking, hiking, skiing, and other attractions. It lists many specific biking and hiking trails for different difficulty levels close to Boulder, as well as ski areas like Eldora and other Colorado resorts. Other activities mentioned include swimming, tennis, pickleball. Locations highlighted include NCAR, Red Rocks, Mt Evans, Flagstaff Mountain, and Eldorado Canyon.