Hozomeen Campground is primitive and it is necessary to pack out all litter and refuse. Ross Lake's limited access helps protect the pristine quality of the lake and its environment. The uniquely-colored waters of Diablo Lake are due to the high concentration of glaciers upstream. Ten percent of the glaciers in the lower forty-eight states grind rock into a fine powder that stays suspended in the lake. Light reflecting off those rock particles causes the intense turquoise lake color.
Thunder Creek is the major stream contributing glacial sediment to the lake.
Diablo Lake is open year round to fishing and boating. Camping is available at Colonial Creek Campground, or by permit at three boat-in sites. Models, photographs and videos demonstrate the variety of plants and animals of the various life zones in the mountains. Wall maps and the relief model at the center of the lobby provide information about the region's geology and vegetation. Explore both the natural and human history of the area on trails near the visitor center.