These maps and mapping softwares are useful for benchmark huntinng.

["Google Earth"]

Free software for accessing satellite views of Earth online.

[http://www.topozone.com/ Topozone]

Online browser for USGS topographic quads. Many benchmarks are indicated on these maps, and experience has shown that the location on the map for "scaled" locations may be more accurate than the location stated on the datasheet.

[http://www.davidrumsey.com/ David Rumsey Historical Map Collection]

Online archive of many historical maps. Some of these can be useful when trying to locate old railroads or other landmarks that have gone missing.

[http://historical.maptech.com/index.cfm Maptech Historical Maps]

Maptech has scanned images of USGS topographic maps from the early 20th century Northeastern states. These are very useful for locating abandoned railroads rights of way. They are also valuable for finding the original alignments of roads that may have been relocated or improved since the time a benchmark was placed

[http://libremap.org/ Libre map project]

The Libre map project offers the entire set of USGS quads available for download.