Erickson was also the head coach of two teams in the National Football League (NFL), the Seattle Seahawks (1995–1998) and the San Francisco 49ers (2003–2004), and tallied a mark of 40–56 (.417).

[1] In 2018, the AAF named Erickson as the head coach of the Salt Lake Stallions, bringing him out of retirement until the league disbanded after eight games of what was meant to be a ten-game season.

As a junior, Dennis was the starting quarterback, beating out the former starter, senior Mike Price, another future college head coach.

Erickson graduated from EHS in 1965 and accepted a football scholarship to Montana State in Bozeman to play for head coach Jim Sweeney,[6] and was a member of the Sigma Alpha Epsilon fraternity.

Beginning at his alma mater MSU in 1971 under Sonny Holland, he became an offensive coordinator in 1974 at the University of Idaho under newly promoted head coach, Ed Troxel, and stayed in Moscow for two seasons.

[10] After two years, Sweeney left to become an assistant with the NFL's Oakland Raiders under John Madden, and Erickson continued at Fresno in 1978 under new head coach Bob Padilla.

When Jack Elway, a former Sweeney assistant at WSU, was hired at San Jose State in 1979, Erickson joined him for three seasons, again as the offensive coordinator.

They instituted the spread offense, which Elway had picked up from his son John's high school head coach, Jack Neumeier.

Erickson's head coaching career began at age 34 at the University of Idaho on December 11, 1981, succeeding Jerry Davitch, who had been fired nine days prior to his final game (a one-point home loss against rival Boise State).

A pre-season playoff pick in Davitch's fourth season, Idaho finished 1981 with six consecutive losses, winless in all seven games in the Big Sky.

Erickson revived Vandal football and quickly turned it into a top I-AA program, whose success was continued for another decade by former assistants Keith Gilbertson (1986–88) and John L. Smith (1989–94).

[21] Expectations were very high at Miami, as Erickson replaced the successful Jimmy Johnson, who had led the Hurricanes to ten or more wins each the previous four seasons and a national championship in 1987 before departing for the NFL's Dallas Cowboys.

In September 1994, the Hurricanes lost, 38–20, to Washington at the Orange Bowl, snapping the Canes' NCAA record 58-game home win streak.

However, when it emerged that an academic adviser had helped players fraudulently obtain Pell Grants, the federal government asked Miami to stop its probe so the Department of Education could conduct an investigation of its own.

[28] In his first season, he switched starting quarterbacks from the #2 overall pick in the 1993 NFL draft, Rick Mirer, and went to John Friesz, whom he recruited to Idaho in 1985.

After the season, Erickson, who had been told by new owner Paul Allen that he would return in 1998, had to fire longtime friend and assistant the special teams coach Dave Arnold and replace him with Pete Rodriguez.

With a revamped lineup led by 1997 passing leader Warren Moon, the Hawks flew out of the gate in 1998 with a three-game winning streak (including a Kickoff Weekend shutout of the Eagles at Veterans Stadium), but stumbled and lost their next three games.

[30] In January 1999, Erickson returned to the college ranks when he was hired at Oregon State University in Corvallis,[31][32] with a five-year contract at $300,000 per year.

His early departure left some OSU fans angry with him for not finishing-out his contract, but he is still credited with playing a leading role in reviving the Beavers football program.

This move was the first strong indicator that the fans believed that John York was not cut out to be the owner of the team after taking over the franchise from his brother-in-law Edward J. DeBartolo, Jr. in 2000.

Erickson had won 32 games in his first four seasons as a head coach (1982–85) to establish Idaho as a top I-AA program in the Big Sky Conference.

After a few days, Holt reconsidered and accepted another job back at USC, as defensive coordinator under Pete Carroll for even more money, more than double his salary at Idaho.

[54] When asked at his introductory press conference if Idaho was indeed a long-term arrangement, Erickson responded, "You want to look at the age on my driver's license?...This, hopefully, is going to be my last job.

Arizona State athletic director Lisa Love hired him on December 9 to replace recently fired Dirk Koetter, who had finished the 2006 regular season at 7–5.

He immediately paid dividends at ASU, leading the Sun Devils to a 10–2 regular season record in 2007, a share of the Pac-10 title, and a berth in the Holiday Bowl.

[58] Erickson's early success at ASU was not sustained, as the Sun Devils failed to have another winning season and lost three of four Territorial Cup rivalry games against Arizona.

In February 2013, Erickson came out of retirement to join the staff at the University of Utah as the co-offensive coordinator with Brian Johnson under head coach Kyle Whittingham.

[60] In 2018, Erickson was named the head coach of the Salt Lake Stallions, a team part of the Alliance of American Football, set to play in 2019.