Fig. 1. Location of geothermal areas (geyser basins) surveyed within Yellowstone National Park, USA. Thirty study sites encompassed active surface‐geothermal zones distributed among eight large areas: Amphitheater Springs (A); Norris Basin (B); Rush Lake/Firehole River (C); White Creek (D); Rabbit Creek (E); West Thumb area (F); Heart Lake (G); and Forest Springs/Mud Volcano area (H). The location of each individual study site is listed in Table 1.