Map of surface uplift at Yellowstone between 1923 and 1975-1978

Upper left: Contours of surface uplift that occurred in the Yellowstone caldera between leveling surveys in 1923 and 1975-77. Lower right: Locations of key benchmarks. The central part of the caldera floor rose more than 700 millimeters (28 inches), at an average rate of 14 millimeters per year (0.5 inch per year). The greatest uplift occurred between the Mallard Lake and Sour Creek resurgent domes, including near Old Faithful (OF, benchmark F10) and LeHardys Rapids (LH, benchmark DA3).