3. Icy Straight Point, Alaska
This zip line claims to be the largest in the world and it may be just that, offering six separate one-mile lines. Six riders at a time take to the top and drop 1,300 feet over 90 seconds. Average speeds hit about 65 miles an hour but the record to date is 82 miles per hour. The ride starts with a 45 minute tour and an eight mile bus ride to the top of the mountain. The views are unparalleled; rugged treetops, mountain peaks and ocean views.