Geologic activity since the Devonian has removed or covered many of the Devonian rocks of North America. However, rocks of this age can be found below the surface in many states, and exposures can be found in northern and central states like New York, Pennsylvania, Ohio, Indiana, and Iowa, among others. Devonian rocks are also exposed in several Canadian provinces and in small areas of northwestern and southern Mexico.
View modern exposures of rock from each time period in North America: