Dr. Daniel T. Blumstein University of California Los Angeles Woodchucks are groundhogs and vice versa. They are one of the 14 currently recognized species of marmots , large ground squirrels found throughout the Northern Hemisphere.
Marmots are rodents, closely related to both ground squirrels and prairie dogs.
Just to be sure, you might want to visit The Squirrel Page . At least 3 woodchucks are reputed to predict the weather. In the Northern US, the responsibility falls upon Punxsutawney Phil. Down South, Beauregard Lee gets the honors. On the Bruce Peninsula of Lake Huron the albino Wiarton Willie tries his luck.