Don’t think the Rockies are volcanic. I can’t find any sources to support that.

From Wikipedia

The current Rocky Mountains arose in the Laramide orogeny from between 80 and 55 Ma.[11] For the Canadian Rockies, the mountain building is analogous to pushing a rug on a hardwood floor:[12]: 78  the rug bunches up and forms wrinkles (mountains). In Canada, the terranes and subduction are the foot pushing the rug, the ancestral rocks are the rug, and the Canadian Shield in the middle of the continent is the hardwood floor.[12]: 78