The Mile-High City might just be one of the best launching points for hiking, climbing, and skiing within the continental United States. Downtown Denver lies well within striking distance of several prominent Fourteeners, including the 14,259-foot local pride and joy Longs Peak, which lies in the heart of Rocky Mountain National Park. And within just an hour's drive of the city, you'll find three canyons, thousands of rock climbing routes, and hundreds of miles singletrack weaving through the high desert and Ponderosa pine forest of the Front Range foothills. Visit in the height of summer to catch the bloom of lupines and golden banner (June through July) or later in the season (August through September) for prime peakbagging conditions and the first blush of the aspens' fall color.