Washington, 1936-1973

This subseries consists of the data collection sheets which were taken to the field to record the water level measurements at the observation wells, typically in the spring and fall of each year from about 1962 to 1975. Many of the sheets have a small photo of the well site stapled to them. Some files also contain sheets of data collected by the USGS. In addition, there are occasionally county highway maps and data charts included. The files are arranged alphabetically by Colorado county or other geographic area.