From the deserts of Arizona to the rocky coastline of Maine, from the sandy shores of Florida to the peaks of Colorado, the United States offers a breathtaking range of natural landscapes. The new National Geographic book Great Outdoors USA: 1,000 Adventures Across All 50 States reveals how to hike, raft, climb, surf, and bike through some of the best of them. Here are 50 of its top picks, one in each state.