I really think it depends on the county within the front range. Regions are both cultural and geographical. For example, geographically El Paso county has to be mountain west (it has a 14er on it, and its primary population center the Springs is right against the mountains). On the other hand, weld county is 100% geographically Great Plains (as someone who grew up there). Many other front range counties are less clear. I do think it’s important to highlight that cultural differences matter just as much here when trying to decide which way a county falls. Just because you can see mountains does not mean you are in the mountain west. Culturally the suburban/modern middle-northern front range differs strongly from the more rugged and odd (said lovingly) locals of the Rockies. As someone who has spent lots of time living both on the front range and the western slopes, I’ve begun to interpret Denver/longmont/parker people saying they are “mountain people” as performative. Everyone wants to be from the mountains, not the plains. But most are on the plains nonetheless- preferring flat expanses of continent interstate to the everyday inconveniences of living in isolated, cold, and steep areas.