Water‐level fluctuations caused by Montana earthquake

The major earthquake of August 17, 1959, near the Montana‐Wyoming border had marked effects on water levels and artesian pressures in wells throughout the United States. Preliminary reports from field offices of the U. S. Geological Survey in 21 states show that water‐level fluctuations were automatically recorded in 136 observation wells. These wells for which records are available, and the maximum double amplitude of the fluctuations, are listed in Table 1.