These contours represent static groundwater levels based on depth-to-water measurements in Smith Valley and Mason Valley, Nevada. Groundwater-level contours for Smith Valley were first published by Rush and Schroer (1976) and subsequently published electronically by Welborn and Medina (2022). The Smith Valley groundwater-level contours represent conditions in the spring of 1972. Groundwater-level contours for Mason Valley were first published by Huxel and Harris (1969) and subsequently published electronically by Lopes and others (2006). The Mason Valley groundwater-level contours represent conditions during 1965-1966. The original groundwater-level contours from Smith Valley and Mason Valley (Huxel and Harris, 1969; Rush and Schroer, 1976) were modified in this study for consistency with the methods used to develop groundwater-level contours by Lopes and Allander (2009) for fall 2006. In the revised dataset, three contours in Smith Valley and 21 contours in Mason Valley were adjusted where they approach and cross the river while maintaining their general form and interpretation away from the river. In this study, because groundwater conditions were generally considered static in Smith Valley and Mason Valley between 1965-72, the two groundwater-level contour datasets are jointly referred to as the 1970 groundwater-level contours.