Set at the end of a private dead-end drive on Flagstaff Road, this octagon-shaped residence rises through four levels on 10.25 forested acres. The road below is one of the best-known climbs in Colorado cycling, and Green Mountain Trail starts steps from the back door, close enough that a morning run means putting on shoes and going.Downtown Boulder is minutes away, but you would never know it. No neighbors in sight, nothing to hear but wind and birds. Longs Peak and the Indian Peaks Wilderness fill the view west, and at night Boulder’s lights spread out far below to the east. 5097 Flagstaff suits someone who has worked hard for this kind of quiet and wants to wake up in the trees without giving up dinner reservations, live music, or a decent grocery run. Some will live here year round. Others will use it as a retreat, for family, for writing, for gathering people somewhere quiet.Each level opens onto something different. The great room has vaulted ceilings, exposed timber beams, and walls of glass that bring the ridge inside. A sunken conversation and dining area sits at the center, the kind of space where dinner runs long. The kitchen was built for real cooking: Viking range, Thermador refrigerator, slate tile backsplash, custom cabinetry. The primary suite opens to a southwest-facing Juliette deck for morning coffee. At the top of the house is the Birdsnest office, ringed in glass with forest and mountain views in every direction. The main level deck wraps several sides of the house, each with a different view.Outdoors, a detached 1,500 sq ft geothermal greenhouse means tomatoes in February and greens all winter. A fully owned solar array powers the property outright. A gas fire pit handles the evenings, horseshoes are set up below the house, and two fenced acres surround it.You can ride Flagstaff before work, hike Green Mountain at lunch, and watch the sun go down behind the Divide from the deck. That is the day this house is built around.