1. Progress of the transcontinental triangulation and reconnaissance : eastward from the Pacific Coast. June 30, 1887 Yale Public content 1887. 2013-10-22T17:39:39Z. 2018-12-10T20:33:47Z. U.S. Coast and Geodetic Survey, issuing body. U.S. Coast and Geodetic Survey. English. cartographic image. Public. Southwest, New.