== Clarification == 

 The first time I tried to reconcile this article with GoogleEarth imagery, I thought the article had serious errors. But then I realized there are 2 "Mount Jefferson"s in Montana, and the one this article refers to is the SOUTHERN one (near the Idaho & Wyoming corners). I also found at least 2 other creeks with similar or identical names; the most-prominent one being ~160km (~100mi) ENE near Red Lodge, MT, which has a road & lake named for it. I don't know how to clarify the article without introducing original research, but it needs to be fixed. The coordiates (which I initially overlooked) appear to be reasonably accurate, but not conspicuous enough within the article.