Bill McCartney, a three-time coach of the year in the Big Eight Conference who led the Colorado Buffaloes to their only national football title in 1990, has died. He was 84.

McCartney died Friday night “after a courageous journey with dementia,” according to a family statement.

“Coach Mac touched countless lives with his unwavering faith, boundless compassion, and enduring legacy as a leader, mentor and advocate for family, community and faith,” the family said in its statement. “As a trailblazer and visionary, his impact was felt both on and off the field, and his spirit will forever remain in the hearts of those he inspired.”

After playing college ball under Dan Devine at Missouri, McCartney started coaching high school football and basketball in Detroit. He then was hired onto the staff at Michigan, the only assistant ever plucked from the high school ranks by Bo Schembechler.

Schembechler chose wisely. As the Wolverines’ defensive coordinator during the 1980 season, McCartney earned Big Ten “Player” of the Week honors for the defensive scheme he devised to stop star Purdue quarterback Mark Herrmann.

“When I was 7 years old, I knew I was going to be a coach,” McCartney told The Gazette in 2013. “My friends, other kids at that age were going to be president, businessmen, attorneys, firemen. Ever since I was a little kid, I imitated my coaches, critiqued them, always followed and studied them.”

In 1982, McCartney took over a Colorado program that was coming off three straight losing seasons with a combined record of 7-26. After three more struggling seasons, McCartney turned things around to go to bowl games in nine out of 10 seasons starting in 1985, when he switched over to a wishbone offense.

His 1989 team was 11-0 when it headed to the Orange Bowl, where Notre Dame dashed Colorado’s hopes of a perfect season. McCartney and the Buffaloes, however, would get their revenge the following season.

After getting off to an uninspiring 1-1-1 start in 1990, Colorado won its next nine games to earn a No. 1 ranking and a rematch with the Fighting Irish. This time the Buffaloes prevailed, 10-9, and grabbed a share of the national title atop the AP poll (Georgia Tech was tops in the coaches’ poll).

McCartney won numerous coach of the year honors in 1989, and he was also Big Eight Coach of the Year in 1985 and 1990. His teams went a combined 58-11-4 in his last six seasons before retiring (1989-94).

The Buffaloes finished in the AP Top 20 in each of those seasons, including No. 3 in McCartney’s final year, when the team went 11-1 behind a roster that included Kordell Stewart, Michael Westbrook and the late Rashaan Salaam. That season featured the “Miracle in Michigan,” with Westbrook hauling in a 64-yard TD catch from Stewart on a Hail Mary as time expired in a win at Michigan. Salaam also rushed for 2,055 yards to earn the Heisman Trophy.

McCartney also groomed the next wave of coaches, mentoring assistants such as Gary Barnett, Jim Caldwell, Ron Dickerson, Gerry DiNardo, Karl Dorrell, Jon Embree, Les Miles, Rick Neuheisel, Bob Simmons, Lou Tepper, Ron Vanderlinden and John Wristen.

“I was fortunate to be able to say goodbye to Coach in person last week,” Colorado athletic director Rick George, who worked under McCartney and was a longtime friend of his, said in a statement. “Coach Mac was an incredible man who taught me about the importance of faith, family and being a good husband, father and grandfather. He instilled discipline and accountability to all of us who worked and played under his leadership.

“The mark that he left on CU football and our athletic department will be hard to replicate.”

McCartney remains the winningest coach in Colorado history. He retired at age 54 with an overall record of 93-55-5 (.602) in 13 seasons, all with Colorado.

He was inducted into the College Football Hall of Fame in 2013. His family announced in 2016 that McCartney had been diagnosed with late-onset dementia and Alzheimer’s.

“Here’s what football does: It teaches a boy to be a man,” McCartney told USA Today in 2017. “You say, ‘How does it do that?’ Well, what if you line up across from a guy who’s bigger, stronger, faster and tougher than you are? What do you do? Do you stay and play? Or do you turn and run? That’s what football does. You’re always going to come up against somebody who’s better than you are.

“That’s what life is. Life is getting knocked down and getting back up and getting back in the game.”

In recent years, McCartney got to watch grandson Derek play defensive line at Colorado. Derek’s father, Shannon Clavelle, was a defensive lineman for Colorado from 1992-94 before playing a few seasons in the NFL. Derek’s brother, T.C. McCartney, was a quarterback at LSU and is the son of late Colorado quarterback Sal Aunese, who played for Bill McCartney in 1987 and ’88 before being diagnosed with stomach cancer in 1989 and dying six months later at 21.

Growing up, Derek McCartney used to go next door to his grandfather’s house to listen to his stories. He never tired of them.

When playing for Colorado, hardly a day would go by when someone wouldn’t ask Derek if he was somehow related to the coach.

“I like when that happens,” Derek said.

ESPN’s Adam Rittenberg and The Associated Press contributed to this report.