USGS
Triangulation Station
"COSTELLO"

1893

Jerry Penry
May 17, 2019

This point is the most northeasterly location in the 1893 USGS triangulation network. It is located approximately 15 miles northeast of Rapid City kin an area of rolling hills. It is also the location of a separate triangulation station established by the U. S. Coast & Geodetic Survey (USC&GS) in 1925. Somehow the USC&GS surveyors thought the spelling for the location should be "Castello" instead of "Costello". A check of the early land documents shows that JOHN COSTELLO homesteaded the NW 1/4 of Section 26, T4N, R8E, which is about 2 miles southwest of the monument's location. Costello was likely the first person in the area, so the monument was named after him.

The 1925 USC&GS monument at left and the 1893 USGS monument to the right.

The 1893 USGS stone (above) and the 1925 USC&GS disk in concrete (below). .

Top of the 1893 stone with letters "USGS" and the "+" marking the exact point.

The 1925 USC&GS triangulation station.

Close up of the USC&GS brass disk with the alternate spelling "CASTELLO" stamped upon it.

Reference mark No. 1 for the 1925 USC&GS triangulation station.

Close up of the Reference Mark that was placed in 1925.

View looking south from the triangulation station locations.

The Azimuth Mark located to the southwest that was placed when the USC&GS triangulation station was established.

The disk of the 1925 Azimuth Mark.

Back to USGS Black Hills Triangulation

© Jerry Penry 2019