Horsetooth Resevoir is beautiful! Located west of Fort Collins in the foothills. It has 1,900 acres of water and is 6.5 miles long. The only thing I don't like about Horsetooth Reservoir is it doesn't have any beach areas to park the boat to stretch your legs and let the kids play. If it had more beach area for boats then this would be my favorite place to boat; so far in Colorado.