These contours represent static groundwater levels based on depth-to-water measurements in Smith Valley and Mason Valley, Nevada, for fall 2006. Groundwater-level contours were first published by Lopes and Allander (2009) and subsequently published electronically by Medina and others (2022). Since the time of the dataset's original publication, the position and land-surface altitude at 23 monitoring wells in Smith Valley used to develop the original 2006 groundwater-level contours have been updated. As such, 10 contours in Smith Valley were revised using the updated monitoring well locations and land-surface altitudes while maintaining, to the extent possible, the original interpretation made by Lopes and Allander (2009).