East of Mississippi River, North of Ohio and Potomac Rivers: Connecticut,
Delaware, District of Columbia, Illinois, Indiana, Maine, Maryland,
Massachusetts, Michigan, New Hampshire, New Jersey, New York, Ohio,
Pennsylvania, Rhode Island, Vermont, Wisconsin
Northwestern
States -- No digital maps available
Northern part of US between western edge of Lake Superior and Pacific
Ocean: Idaho, Iowa, Kansas, Minnesota, Missouri, Montana, Nebraska, North
Dakota, Oregon, South Dakota, Washington, Wyoming
Southwestern
States -- No digital maps available
Southern US West of Mississippi River: Arkansas, Arizona, California,
Colorado, Louisiana, Nevada, New Mexico, Oklahoma, Texas, Utah
