Tad: As you can see from the topo map, the top of Mount Tallac is just over 9,700 feet. The parking lot was at about 6,500 feet. The elevation change was just about 3,000 feet over about six miles. A fairly strenuous hike! I think we followed the trail which came in from the bottom left corner of the map, past Gillmore lake (where we stopped for a swim), and on to the summit. The return trip was the same.