Utah's Lake Powell is a controversial manmade dam that occupies what used to be the very scenic Glen Canyon. Love it or hate it, the dam provides much-needed water stability in an arid area and, as a bonus, it also provides a fantastic facility for outdoor enthusiasts. You can explore the shores of the lake on foot along a network of hiking trails and spend a few nights in one of three campgrounds suitable for both tents and RVs. Watersports are the most popular activities on the lake and include boating, kayaking, canoeing, waterskiing, and tubing. For something really different, you can rent a houseboat and spend a few days exploring the stunning scenery of the lake from a completely different perspective.