Lake Sheelar, in Clay County, Florida, U.S.A. (29 degrees 50'21.473 lat. and 81 degrees 57'28.201 long). This is an acidic oligotrophic lake in Gold Head State Park that is sampled by the St. John water management district. Photo from old ASLO slide collection; taken by M. Brenner; scanned by K.L. Schulz.