- Tardieu, Pierre Antoine, 1784-18692
- Taride, A2
- Taylor, Richard B.2
- Tennessee. State Geological Survey2
- Tharp, W. E. (William Edgar),cartographer,surveyor.2
- Tharp, W. E.(William Edgar), cartographer.2
- The Farmer [magazine] (Publisher)2
- Tufts, Wm. O.2
- Twiss, W. Patrick2
- Tyrrell, Joseph Burr, 1858-19572
- U.S. Lake Survey, issuing body2
- United States. Adjutant-General's Office. Military Information Division2
- United States. Army. Engineer Regiment, 29th2
- United States. Bureau of the Census2
- United States. Congress. Senate (34th, 1st Session : 1855)2
- United States. Congress. Senate (48th, 1st Session : 1883)2
- United States. Department of Agriculture. Division of Publications2
- United States. Forest Service. California Region2
- United States. Forest Service. Intermountain Region2
- United States. Office of Explorations and Surveys, director.2