Three years after joining the PRCA, Mortensen competed at the
National Finals Rodeo (NFR) and won the first of his six saddle bronc riding world championships. He went on to win the saddle bronc titles in 1994, 1995, 1997, 1998 and 2003. His six titles ties him for most all time with the legendary cowboy
Casey Tibbs. During his 1998 NFR run for the saddle bronc championship, Mortensen became the first rider in PRCA history to win over $200,000 in a single event. The following year,
Sports Illustrated named Mortensen one of Montana's top ten athletes of the century. Mortensen claimed another first in rodeo history at the 2003
Pendleton Round-Up rodeo in Pendleton, Oregon, by becoming the first rough stock rider to exceed $2 million in career earnings. Rodeo was included as a cultural event at the
2002 Winter Olympics in
Salt Lake City, Utah. Mortensen participated on the U.S. team in competition against the Canadian team. He took home the
bronze medal for the competition. The Montana Pro Rodeo Hall of Fame honored Mortensen in October 2002 with the unveiling of an 18' statue of him riding the bronc Tee Box, as the center piece of their Wall of Fame monument at the Metra Park in Billings, Montana. The sculpture was the last work of western artist and fellow Montanan, R.F. Rains. At a ceremony in
Colorado Springs, Colorado, on July 9, 2009, Mortensen was inducted into the ProRodeo Hall of Fame. Mortensen now coaches the Northwest College Rodeo Team in Powell, Wyoming, where he attended college for his first two years of schooling. ==Honors==