Good question! (I’m looking at you Mr. Jindal…)
Here’s a list compiled a few years back from Volcanoes of North America: United States and Canada, by Wood and Kienle. They list all volcanoes that are younger that 5 million years old and are morphologically distinct. If your state is not listed it probably means there are no volcanoes there or they are the remnants of something older than 5 million years! (let the floods commence)
According to them, there are about 262 volcanoes and volcanic fields in North America.
| Location | Number of Volcanoes |
|---|---|
| Canada* | 21 |
| USA* | 241 |
| Alaska* | 108 |
| Arizona* | 9 |
| California* | 24 |
| Colorado* | 1 |
| Idaho* | 6 |
| Hawai’i* | 19 |
| Nevada* | 7 |
| New Mexico* | 16 |
| Oregon* | 34 |
| Utah* | 6 |
| Washington* | 9 |
| Wyoming* | 2 |
there are 241 volcanoes in the USA