Containing a namesake national park in Colorado, this is, for 10 points, which largest mountain range in the western United States?
The Front Range and Clark Range are branches of this larger mountain range. Yoho National Park and Jasper National Park lie within this range, which also contains the sources of the Peace and Fraser rivers.  At its southern terminus, the Sierra Madre range begins.  The highest peak in this range is Mt. Elbert, which lies in the same state as a more notable mountain in this range, Pikes Peak.  Containing a namesake national park in Colorado, this is, for 10 points, which largest mountain range in the western United States?
The Front Range and Clark Range are branches of this larger mountain range.
{Rocky} Mountains or the {Rockies}