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The most frequently used maps for hikers and climbers has always been the the excellent set of USGS topographical maps covering all of the United States, usually down to the 1:24,000 Quad scale. All of these maps, both current and historical, are available online at The National Map, a site with an abundance of other mapping resources. This User Guide is a good place to start to access these maps.
In the Northwest, Green Trails and Custom Correct maps are popular with hikers because they highlight maintained trails and have been updated more frequently than the USGS topos. The map collection includes nearly a full set of older versions of these maps which can be interesting for researchers investigating the state of the trail system as it was when each map was published. Current versions of Green Trails and Custom Correct maps are not being added to the collection, but we would welcome donations of maps in good condition.
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