United Airlines have round trip airfares travelling to and from Sioux Falls SD (FSD) and Denver (DEN) for $ 97, nonstop. These are basic economy fares, a restricted-type fare.

Travel Availability:

Departs FSD: Jan 20, 27-28; Feb 3-4, 16-18, 23-25; March 2-3, 10,1 2, 15-17, 20-24, 26, 29, 31; April 2, 7, 14, 16, 20-21, 23, 28, 30; May 5-7, 10, 12-14, 19, 24, 28, 31; June 2, 7, 9
Departs DEN: Jan 21-24, 28-31; Feb 1, 4-7, 9-13, 19-21, 25-27; March 3-5, 8, 10-12, 17-19, 24-29, 31; April 1-3, 7=9, 12, 16, 21-23, 26, 28-30; May 5-7, 9, 12, 14, 19-20, 24, 26-28; June 2, 4, 9