| A.M.E. Church, Rock Springs | Brie Blasi |
| Ada Magill Grave | |
| Ada Magill Grave | WyoHistory.org |
| African-American women voters, early Wyoming elections | Wyoming State Archives |
| Airmail, U.S. in Wyoming | Steve Wolff |
| Aladdin Coal Tipple | |
| Aladdin General Store | |
| Albany County courthouse | |
| Albany County, Wyoming | Marguerite Herman |
| Albert, Prince of Monaco, hunts with Buffalo Bill, 1913 | John Clayton |
| Alcova Dam and Reservoir | Annette Hein |
| Alcova Lake | |
| Alfred Corum Grave | |
| Allred, Golden, Bighorn Basin trapper | Washakie Museum and Cultural Center |
| Alvah Unthank Grave | |
| Amelia Earhart monument | |
| American Heritage Center | |
| American Indian geography in Wyoming | Gregory Nickerson |
| American Indian tribes, trade among | Samuel Western |
| Ames Monument | |
| Ames Monument | WyomingHeritage.org |
| Anchor Dam | |
| Anchor Dam, History of | Annette Hein |
| Anderson, A.A. | John Clayton |
| Anna Miller Museum | |
| Antlers Hotel | |
| Arapaho tribe, arrival of on Shoshone Reservation, 1878 | WyoHistory.org |
| Archeology, alpine in Wyoming | Rebecca Hein |
| Arthur, Chester A. and 1883 trip to Yellowstone | Dick Blust, Jr. |
| Astorian Expedition informative sign | |
| Atlantic City, Wyo. | |
| Atlantic City, Wyo. | Lori Van Pelt |
| Averell, Jim, newspaper reporting of the lynching of | Tom Rea |
| Ayres Natural Bridge | |
| Ayres Natural Bridge, Oregon Trail site | WyoHistory.org |
