| Diamond Hoax, 1872 | Encyclopedia | Dick Blust, Jr. |
| Diamond L. “Slim” Clifton site | Field Trips | |
| Dick Cheney Alumni Field | Field Trips | |
| Dick Cheney Federal Building | Field Trips | |
| Dickinson, Anna, speaks in Cheyenne, 1869 | Encyclopedia | Tom Rea |
| Dinosaurs | Encyclopedia | Annette Hein |
| Dixon, Joseph K. | Encyclopedia | Johanna Wickman |
| Douglas Railroad Interpretive Center | Field Trips | |
| Downey, June Etta, longtime University of Wyoming psychology professor | Encyclopedia | Rebecca Hein |
| Downey, Stephen Wheeler | Encyclopedia | Tyler Eastman |
| Dry Farming | Encyclopedia | Carl V. Hallberg |
| Dry Sandy Crossing | Encyclopedia | WyoHistory.org |
| Dubois Museum | Field Trips | |
| Dude ranching, history of in Wyoming | Encyclopedia | John Clayton |
| Dull Knife Fight, 1876 | Encyclopedia | Gerry Robinson |
| Durand, Earl, Park County poacher and bank robber | Encyclopedia | Lillian Turner |
| Durlacher House | Encyclopedia | Stephanie Lowe |
| Durlacher House | Field Trips | |
| Earhart, Amelia, Wyoming connections of | Encyclopedia | Lori Van Pelt |
| Eastern Shoshone Tribe, 1905 Land Cession Agreement | Encyclopedia | WyoHistory.org |
| Eastern Shoshone, two Fort Bridger treaties with | Encyclopedia | WyoHistory.org |
| Eclipses, solar | Encyclopedia | Rebecca Hein |
| Ecoffey family and 1868 wagon train attack | Encyclopedia | Rebecca Hein |
| Edison, Thomas in Wyoming Territory | Encyclopedia | Phil Roberts |
| Eisenhower, Dwight and 1919 transcontinental motor convoy | Encyclopedia | Lori Van Pelt |
| Elizabeth Cumming | Encyclopedia | Rebecca Hein |
| Elizabeth Paul Grave | Field Trips | |
| Elk Basin Oil Field | Encyclopedia | Rebecca Hein |
| Elk Mountain Hotel | Encyclopedia | Lori Van Pelt |
| Elk Mountain Hotel | Field Trips | |
| Elk Mountain Museum | Field Trips | |
| Ellis, Frank “Pinky” on the sheep business, small-town politics and family life | Oral Histories | Casper College Western History Center |
| Emerson, Frank | Encyclopedia | Wyoming State Archives |
| Emigrant Gap | Field Trips | |
| Emigrant Gap, Oregon Trail site of | Encyclopedia | WyoHistory.org |
| Emigrant Hill, Oregon Trail site | Encyclopedia | Randy Brown |
| Emigrant Spring, Oregon Trail Slate Creek Cutoff site | Encyclopedia | Randy Brown |
| Empire, Wyoming, African-American community of | Encyclopedia | Robert Galbreath |
| Encampment, Wyoming | Encyclopedia | Lori Van Pelt |
| Energy Transportation Systems, Inc. coal slurry pipeline | Encyclopedia | Dan Whipple |
| Ephraim Brown Pioneer Grave | Field Trips | |
| Ephraim Brown, homicide victim, pioneer grave of | Encyclopedia | Randy Brown |
| Equal Rights Amendment, Wyoming and | Encyclopedia | Wyoming State Archives |
| Equal Rights Amendment, Wyoming ratification debate around | Encyclopedia | Rebecca Hein |
| ETSI coal slurry pipeline | Encyclopedia | Dan Whipple |
| Evans, Loren | Encyclopedia | Rebecca Hein |
| Evanston, Wyoming | Encyclopedia | Barbara Allen Bogart |
| Expedition Island | Field Trips | |
| F.E. Warren ICBM & Heritage Museum | Field Trips | |
| Farlow, Ed and Tim McCoy with Wind River Indians on stage and screen | Encyclopedia | Rebecca Hein |
