Early U.S. Geological Survey Monuments 1897 Triangulation
In 1897, the U. S. Geological Survey came back to the Black Hills region of South Dakota to continue their triangulation network begun in 1893. (See work done during that year: USGS 1893 Triangulation). The work in 1897 was done by Frank Tweedy during the months of October, November and December. This network hinged upon the 1893 points of Bradley, Harney, Custer, and Bear Butte. Work was done with an 8-inch Fauth micrometer theodolite. The weather was reported to be extremely cold, stormy, and windy, with the observations not always being good. The error of closure was reported to be about 5-seconds. Nine stations were placed in 1897 which were named Bear Springs, Lookout, Terry, Crows Nest, Crow Peak, Sullivan, Elk, Newcastle, and Alkali. A meridian line was established at Deadwood.
UNITED STATES
GEOLOGICAL SURVEY
(South Dakota)
Black Hills Region
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© Jerry Penry 2015