USGS: Historical Maps at Your Fingertips

USGS: Historical Maps at Your Fingertips. “TopoView 2.1 is a modern web application built on an open source mapping platform that is free of charge. The highly interactive service provides tools and procedures that allow users to easily find historic map scans from USGS’s Historical Topographic Map Collection and even compare those with modern day maps. The new version is full of improvements and advancements based on hundreds of user comments and suggestions.”