On the 120-yards-by-53-yards-and-one-foot space inside the boundaries of a football field, and far beyond them, too, Dennis Erickson has witnessed just about every-darn-thing there is to see. He’s experienced darn near everything there is to feel and know.

“This,” he said, “is a new adventure.”

The latest in a professional life full of them.

In the run-up to mentoring the Stallions, Erickson coached at high schools in three Western states. He coached at colleges — in the mountains, in the desert, on the coast, on the other coast, in the mountains, again, in leagues like the Big Sky and the Big East and the WAC, in the Pac-10 and the Pac-12. He won a couple of national championships at Miami. He helped a storm-ravaged community find hope in rallying around a winner, when Hurricane Andrew destroyed thousands of homes in South Florida, including his own.

He coached two NFL teams — the Seahawks and the 49ers — and previously turned down offers from two others — the Eagles and the Broncos. He’s lived through great glory and competitive heartbreak. He’s hoisted trophies and packed his bags, won conference titles and hacked through controversy, such as a Pell Grant scandal at Coral Gables. He’s been praised — named his league’s coach of the year at Arizona State — and ripped — sent away a few seasons later. He’s been hired, fired, hired, fired, hired, fired and hired, over and over.

He’s made a lot of money, and, at times, made virtually nothing as a volunteer.

He’s been in the blaring spotlight, and in the obscure corners of his profession.

He’s endured fame and infamy.

“I met Bear Bryant,” Erickson once told me. “I bowed. The guy was god.”

The one constant in his life — he turns 72 next month — has been football, a deep passion for a game his father, Robert, also a coach, began teaching him six decades ago.

He’s coached it for most of the years since.

All the way back when he was a college quarterback at Montana State in the 1960s, he gripped the football day after day after day, never realizing until many years later that all along, in truth, the football was gripping him.

Even when Erickson has tried to walk away, he always comes back. Or football boomerangs back to him. He’s personified the words of the Eagles’ — the band, not the team — song, Hotel California. He can check out any time he wants, but he can never leave.

And so, he hasn’t.

Now, he’s Salt Lake’s head coach. His old NFL friend Bill Polian talked him into jumping on this last new job, and he was thrilled to do the leaping.

“What else would I do,” he said.

Al Hartmann | The Salt Lake Tribune Assistant head coach Dennis Erickson coaches the running backs during practice Monday August 17. Head coach Kyle Whittingham, behind.

Erickson used those exact words — it was more of a statement than a question — nearly seven years ago, when he first was hired by Kyle Whittingham as Utah’s offensive coordinator. At that juncture, he had coached for a mere 44 years, and still hungered for his game.

After four years as an assistant at Utah, Erickson did retire from coaching, but even then he worked from his home in Coeur d’Alene, Idaho, as an adviser to his son, who is a high school coach. When the AAF was formed last fall, and Erickson discussed the fine points of the league with Polian and Steve Spurrier, who coaches the AAF’s Orlando Apollos. The coaching vet was interested and intrigued. Next thing, he was in it, inked to a contract.

“It sounded like fun,” he said. “Coaching is what I do. You can only play golf and go fishing for so long. I’m excited about it.”

Erickson was in on the project from the beginning. He helped put the team together, and had been coaching the Stallions in San Antonio, its preliminary base over the AAF season’s first two weeks. The team, all its coaches, its management, its players, its equipment, moved to Salt Lake City on Thursday, looking ahead to its first home game against Arizona at Rice-Eccles Stadium on Saturday. Thus far, the Stallions are 0-2, showing the rudiments of a strong defense in those road games, but the offense has sputtered, in part because of injuries.

No big thing, Erickson said. The loose pieces will come together in time.

The coach said he rates the play in the AAF as “high college level, maybe even higher.”

“It’s Triple-A pro football,” he said. “A lot of the guys have played in the NFL. The brand of football is really good, the players and coaches are good. To me, it’s pure football. I’m having a lot of fun with it.”

And he plans on continuing to do so.

Erickson scoffed at recent reports that claimed the Alliance already is in monetary despair and disrepair: “We’re in good hands financially. Nobody’s worried about it. The guy who came in — Tom Dundon [owner of the NHL’s Carolina Hurricanes] — wanted to invest $250 million. He was already involved before this became public.”

The AAF, then, is for players who want a chance to further a dream, and for people who are still thirsty to watch quality football, after the college season is over, after the NFL playoffs end, after the Super Bowl is done, for those who miss the game in the spring.

People like Erickson, who enjoys his life away from football, too, hanging out at the lake-side cabin in Idaho, goofing around with the grandkids, doing some golfing and fishing, and during the traditional fall season, watching Utah and BYU football on television, in addition to NFL games.

“I’m a couch potato on Saturdays,” he said. “I have three TVs and a clicker,” he said. “It’s fun watching my friend Kyle coach at Utah and my friend Kalani [Sitake] coach at BYU. I go visit some of the places I used to coach — places like Miami and Oregon State and others. And I live my life. It’s a good life.”

It’s even better now, on account of a new opportunity with a new team in a new league that needed him and wanted him to go on doing what he does, doing what he’s always done.

The statement remains: What else would he do.