The Dresbachian is the lower stage of the Late or Upper Cambrian in North America, equivalent to the Chinese Gushanian which spans about 4 million years, from 501 to about 497 m.y.a. The term comes from the town of Dresbach which is located in southeastern Minnesota on the Mississippi River. The Dresbachian overlies the Middle Cambrian Albertan Series, and is the lowest stage of the Upper Cambrian Croixan series, followed by the Franconian.