Requirements include a 21 day advance purchase on domestic tickets and require a Saturday night stay to qualify. Although specific cities may not be listed low fares are still availble.
A sample fare searched today included a ticket for for $390 between Fargo and Washington, DC and $250 between Fargo and Madison, WI. Other examples from Delta.com include $139 each way from Bismarck to Salt Lake City, UT and Minneapolis to Chicago for $59 each way.
Baggage fees are additional. For more information visit www.delta.com