A lake had replaced the glacier by the time Mt. Mazama's eruption sent a glowing avalanche of frothy pumice and hot gases racing at freight-train speed toward the North Umpqua River canyon. The lake did not vaporize under that hot blast, perhaps because smaller, earlier eruptions had left a thick blanket of pumice floating on the lake's surface as an insulating bridge. Ducks, shadowy trout, and zillions of dragonflies patrol the lapping shore of Diamond Lake. Raucous gray jays and scampering golden-mantled ground squirrels watch passersby. The lake is stocked to provide three million catchable trout each year.
Boats are limited to ten miles per hour.
Pass through Tokelee and Clearwater. Turn here and drive past the boat ramp before parking on the left at the Diamond Lake Lodge. The compound includes not only a restaurant and store, but also a marina shop where you can rent boats and bicycles. The lake has an average depth of only 20 feet, so it becomes swimmably warm in August. After 1.7 miles, the trail briefly joins a road to cross Lake Creek, the lake's outlet.