- Geological Survey (U.S.)
- Digital Commonwealth
- Boston Public Library
- U.S. Geological Survey
Relief shown by contours, isolines and spot heights. Surveyed in 1890. Henry Gannett, chief topographer; R.U. Goode, geographer in charge; triangulation by U.S. Coast and Geodetic Survey; topography compiled by H.L. Baldwin Jr. from U.S. Coast and Geodetic Survey, and U.S. Public Land Surveys.
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