Confluence Pryor Creek and Yellowstone River
© 2001 Airphoto, Jim Wark. All rights reserved.
Pryor Creek joins the densely braided Yellowstone River from the south (the viewer's left; the Yellowstone is flowing toward the viewer), fifteen or sixteen miles below the point where it is believed Pryor crossed the Yellowstone, at today's Billings, Montana. Pryor Creek begins about fifty straight-line miles away, in Pryor Gap in the Pryor Mountains, but coils into nearly 100 miles of creek bottom by the time it empties into the Yellowstone.
Local lore maintains that Pryor traveled up this creek to the mountains, that he "drew the mountains and the creek on the map he was making," and "decided to name them both in honor of himself."1 Not only is there no evidence whatsoever in the expedition's journals that he explored the creek, but also it would have been entirely inconsistent with his modest character to have named anything after himself. In any case, he would have passed north of today's Pryor Mountains. Besides, Clark didn't cross the creek he named for Pryor until the day after they went their separate ways, so he didn't even know its name when he crossed it.2 George Drouillard, who returned to the Yellowstone with Manuel Lisa's fur trading party in 1807, followed part of it.
No one is certain who applied Pryor's name to the mountains, the "gap," and the town, nor when.