Dan started wrestling at the age of five, and he continued wrestling until he began Mixed Martial Arts, joining Real American Wrestling (RAW) and then Ultimate Fighting.

In high school, Dan placed second in the 1987 California State Championships and his Victor Valley team won the state team title. He finished fifth in 1988.

Dan won a Community College state championship and helped his Victorville team capture the team title. He also attended California State University, Fullerton, from 1988 to 1990.

He won the USA Junior Nationals in both freestyle and Greco-Roman in 1988, finishing with only one bad mark against him in 23 matches while scoring 120 points, and he won the USA FILA Junior World Greco-Roman Championships in 1990.

After wrestling in Russia in 1991, Dan attended Arizona State and received his bachelor's degree.

Dan won the World University Greco-Roman Championships in 1991, 1992 and 1993. He competed in Greco-Roman at the Olympics in 1992 and 1996, finishing 10th in 1992. He represented the United States in Greco-Roman at the World Championships in 1994 and 1997, finishing seventh.

He began training in MMA in 1997 with RAW and won the Brazilian Open in his first year of competition. A year later he joined Ultimate Fighting and won the UFC 17 tournament, defeating Allan Goes and Carlos Newton. In 1999, he defeated five opponents in two events to earn the RINGS King of Kings title.

Dan, who currently holds the welterweight and middleweight Pride Fighting Championships, credits wrestling and Team Quest for his success.

After leaving UFC, Dan signed a four-fight deal with Strikeforce.

When not training, Dan appreciates his wife Alison and their children: Sierra, 10, Reese, 8, and Daniela, 2.