Mildren, who had been undergoing treatment for stomach cancer, died at Integris Baptist Medical Center, spokeswoman Brooke Cayot confirmed. Mildren was diagnosed two years ago with cancer but had continued to serve as a vice chairman for Arvest Bank and host a daily sports radio show on WKY 930-AM. Legislators at the state Capitol observed a moment of silence for the former lieutenant governor, who walked the halls there in the 1990s. He ran for governor in 1994 as the Democratic Party nominee but lost to Republican Frank Keating. Mildren was the quarterback for Oklahoma's high-powered offense in 1971, when the Sooners set an NCAA record that still stands by averaging 472.4 rushing yards. Mildren had arrived in Norman out of Cooper High School in Abilene, Texas, where he set passing records. But as a junior at OU in 1970, the Sooners got off to a sluggish start and coach Chuck Fairbanks switched to the wishbone offense. The Sooners racked up 5,196 yards on 813 rushes that season, finishing 11-1 by defeating Auburn in the Sugar Bowl. Oklahoma's only loss came in the so-called "Game of the Century," when top-ranked Nebraska beat the second-ranked Sooners 35-31 despite four touchdowns from Mildren -- two rushing and two passing. Mildren finished the season with 1,289 yards rushing -- the most in school history for a quarterback -- and 20 touchdowns before being drafted by the Baltimore Colts.