This Technical Reference contains the rangeland inventory and monitoring techniques historically used in the Bureau since the formation of the Grazing Service. It does not include local or regional techniques. Where manuals could not be located, the best available documentation was used.

The Twin Lights stand at the north and southeast sides of Thacher Island. The island, located about one mile off the coast of Rockport, Massachusetts, is comprised of about 50+/- acres of rock, covered by a minimal amount of land cover. The island is located about 30 miles north of Boston, and about two miles from Gloucester Harbor. A small number of late 19th century wooden houses and structures are clustered near the southeast light tower. The south tower and southeastern portion of the island, about 28 +/- acres, is maintained by the Coast Guard as of 2000. The north tower and northern end...