1. Bedrock geologic map of the Grafton quadrangle, Worcester County, Massachusetts Author/Creator: Walsh, Gregory J. Publication/Creation: [Reston, Va.] : U.S. Geological Survey ; Denver, Colo. : For sale by U.S. Geological Survey, Information Services, 2011 Resource Type: Map Access & Availability: Loading
2. Bedrock geologic map of the Grafton quadrangle, Worcester County, Massachusetts Author/Creator: Walsh, Gregory J. Publication/Creation: [Reston, Va.] : U.S. Dept. of the Interior, U.S. Geological Survey, 2011 Resource Type: Map Access & Availability: Loading