The Denver Chanel and Summit County Search and Rescue teamed up to test out GPS trackers designed to pinpoint people in the backcountry in need of rescue. Â The GPS unit worked quite well during the test and could be a valuable backup strategy in case of emergency, especially in areas with spotty cellular coverage. Glen Kratz of Summit Country Rescue highly recommends bringing one alone if you are on multi-day backpacking trips or just a day tripper who would like family and friends to have a piece of mind.