That's a tricky question! While most mountain ranges in the western United States are associated with volcanic activity, there are a few that are not directly formed by volcanoes.

Here's why it's hard to give a definitive answer:

* "Volcano" is broad: A mountain can be formed by volcanic activity even if it doesn't have a cone-shaped volcano on top. There might be ancient volcanic formations, or the mountain could be formed from uplifted bedrock that was once part of a volcanic area.

* "Mountain Range" is also broad: Some mountain ranges are very complex, with different parts formed by different processes.

Here are some possibilities:

* The Sierra Nevada: The Sierra Nevada is primarily formed by the uplift of granitic rocks, not volcanic activity. However, there are extinct volcanic areas within the range, like the Mono Craters.

* The Wasatch Range: The Wasatch Range in Utah is primarily formed by the uplift of sedimentary rocks, although there are some volcanic formations associated with the range's history.

To be really sure, you'd need to look at the specific geological formation of a mountain range and consider its entire history.