I know what you mean, SRS. I plan to use volcanoes near Phoenix (due south of Stanfield) in my project. There's also a grand flow near Grants, New Mexico.

There's lots of basalt right in Phoenix, but it's weathered to a pinkish-tan color and lacks the drama. At least, that's how it looks in photographs.

There is a program called Google Earth that shows features like this. I don't know how detailed the free program gets, but it's worth looking into.