TUESDAY

Boulder Cycling Club Tuesday Night Ride -- Road bike ride averaging 25 miles at 13 to 16 mph, route changes weekly, recreational no drop ride with leader. Boulder Beer Company, 2880 Wilderness Place, Boulder; free 6 p.m. Details: 303-875-2241.

Hike at Sunset -- Weekly nature hikes with volunteer naturalists interpreting each park's history, geology, ecosystems, plants and wildlife. Sunset hikes involve about 2 miles of moderate hiking; children must be accompanied by an adult; no pets permitted. Lichen Loop Trail, Heil Valley Ranch, 81 Geer Canyon Drive, Boulder; free; 6:30 p.m. Details: 303-678-6214.

WEDNESDAY

Fleet Feet Ladies Run -- Join Fleet Feet for a girls only 3-5 mile run or run/walk; all abilities welcome. Fleet Feet Sports, 2624 Broadway, Boulder, free; 6 p.m. Details: 303-939-8000.

How to Climb a 14er/High Altitude Hikes -- Learn the basic essentials and know-how to tackle the Colorado giants, including food, equipment, training, weather and safety considerations. REI Boulder, 1789 28th St., Boulder; free; 7 p.m. Details: 303-583-9970.

THURSDAY

Freeman Myre Corporate Challenge -- The Freeman Myre Corporate Challenge is an open 5K race at the Colorado Technology Center in Louisville benefiting the "I Have a Dream" Foundation of Boulder County. Colorado Technology Center, 168 CTC Blvd., Louisville; registration 4-5:45 p.m., Sunset 5K at 6 p.m., Elite Race follows at 6:45 p.m.; 6 p.m. Details: 720-841-5422, or www.fmcorporatechallenge.com