"We're coming home," Harsin said in a statement issued by the university. "One of the hardest decisions we ever made was leaving Boise. We did that so I could become a better coach, so I could one day have the opportunity to return as head coach that day has arrived."
It didn't take long for Coyle to find a successor to Petersen, who left last week to take over at Washington.
Coyle focused his search on coaches with ties to the program, including former Broncos head coach Dirk Koetter, now the offensive coordinator for the Atlanta Falcons. University officials have not yet released salary and contract information for Harsin.
"We are extremely excited in our selection of Bryan Harsin as the next head football coach at Boise State," Coyle said. "Bryan is one of the top young head coaches in college football and we are thrilled to bring him back to Boise to lead the Bronco program."
In his only season at Arkansas State, Harsin led the Red Wolves to a 7-5 record and a share of the Sun Belt Conference title. The team will also play Ball State in the GoDaddy.com Bowl later this month.
His five-year contract at Arkansas State carries a $1.75 million buyout clause if he stepped away in the first year of the deal. His departure also makes him the third straight Red Hawks head coach to leave after one year, following Hugh Freeze and Gus Malzahn.
It was during Harsin's tenure as offensive coordinator at Boise State that the team put together its most impressive string of victories and emerged as a BCS contender.
During his tenure, Harsin oversaw an offense led by quarterback Kellen Moore, who won 50 games as a starter to become college football's winningest quarterback. Between 2006-2010, the Broncos put together a 61-5 record, won two BCS bowls, won at least 12 games in four seasons, went undefeated in 2006 and 2009 and led the nation in scoring in 2009.
He should also be familiar with a handful of the Broncos upperclassmen, including junior quarterback Grant Hedrick, who was recruited by Harsin before leaving for Texas and the front-runner to be the starting quarterback next fall.
Harsin left Boise State in 2010 to become the offensive coordinator at Texas, helping a team that finished 88th in the nation in scoring before his arrival to improve to 24th in just two years.
But in Boise, Harsin takes over a team that posted its worst record in nearly a decade despite projections it would win the Mountain West Conference title. Hurt by injuries to its starting quarterback and a young defense, the Broncos finished 8-4 and missed out on the conference title game.
"I appreciate the history and tradition of the Boise State program," said Harsin, a graduate of Capitol High in Boise. "I embrace the success but won't rest on it. We will build this program every day with a sense of urgency."