This article suggests that the most likely transportation system of the sandstone across the continent would have been a river system. Could it have been due to tectonic movement instead?

Edward B. Fan
Upper Marlboro, Md.

Both Utah and the Appalachians are on the North American plate, so there’s no tectonic boundary between them. Sediments from the East could have been deposited and then remobilized at innumerable locations on their way to Utah .–S. Perkins