Yeah, another of them.
Even as a geologist I hadn't bothered with distinguishing between the Absarokas and Beartooths, other in general geologic terms. But I'm spending lots of time in and about them these days so it's worth working at it a little harder.
Arthur Beven best summarized it in a 1923 Journal of Geology article (and later confirmed and refined by Blackstone in 1886):
"The Beartooth Mountains are in southern Montana and north- western Wyoming, where they form the front range of the Rocky Mountains. The range has the approximate form of a broad, much elongated, slightly curved oval which extends southeasterly from Yellowstone Valley above Livingston to the canyon of the Clark Fork of Yellowstone River, about 30 miles northwest of Cody, Wyoming (Fig. i). It is about 80 miles long and has a maximum width of about 30 miles south of its central portion, northeast of the northeast corner of Yellowstone Park. The boundary between the range and the Great Plains is sharply marked (Figs. 2 and 3) but the boundary on the southwest is much less definite. South of the state line the Clark Fork is taken com- monly as the line of demarcation between the Beartooth Mountains and the Absaroka Range to the west. In Montana the two ranges merge more or less, which makes it difficult to draw a sharp natural boundary between them. For this discussion the boundary is taken mainly along the divide between the streams that flow south and west to Yellowstone River and those that pursue a northerly course across the greater portion of the Beartooth Mountains to the same river far beyond the front of the range. Inasmuch as this boundary roughly follows the structural limits of the range, it is less arbitrarily chosen than may appear from this statement".
I made a map to share if I can figure out how to post it - CHEERS!