| Shoshone Reservation, 1905 Land Cession Agreement | WyoHistory.org |
| Siberia, 2nd Lt. Paul Kendall’s service in, 1919-1920 | Douglas R. Cubbison |
| Simpson, Milward | Wyoming State Archives |
| Simpson, Milward - interview | Wyoming State Archives |
| Simpson’s Hollow | WyoHistory.org |
| Sixth Crossing of the Sweetwater, Oregon Trail historic site | WyoHistory.org |
| Smith, Nels | Wyoming State Archives |
| Snodderly, Quintina, Oregon Trail Grave of | WyoHistory.org |
| Solier, C.H., Wyoming State Hospital superintendent | Rebecca Hein |
| Spence, Gerry | WyoHistory.org |
