There are 2 species of Jackelopes. Those antlers came from the eastern Whitetailed jack. Most of them throughout the mountain region are the black tailed variety. These photos were taken in the spring after they'd shed.
whitetailed
blacktailed
RC, I think you clearly misidentified the bottom picture. It’s a Mule Jackalope...Grin 😎
Curiosity Killed the Cat & The Prairie Dog “Molon Labe”