It was 33 years ago, and Gerry Austin still remembers the call. He was a high school principal in North Carolina, getting ready for the dismissal bell to ring at the end of the day -- March 4 at 3:02 p.m. -- when Austin learned he would become an official in the National Football League.

"I can still tell you what day, what time and what I was doing when I got that phone call," said Austin, who officiated in the NFL from 1982-2007. "I think that's true for everybody taken in the NFL."

It is true for Sarah Thomas. She remembers exactly when she learned she would become the first female official in NFL history.

Sarah Thomas will be one of nine rookie NFL officials in 2015. AP Photo/Stephen Brashear

"That call came Thursday, April 2 at 10:47 a.m.," said the 41-year-old Thomas. "And when I looked at my phone, and it was area code 212, I was just praying that it was [NFL vice president of officiating] Dean Blandino on the other end of the line, and it was, and he just said it was an honor for me to have received it.

"So I tell my girlfriends and family that I was speechless, and it's hard for them to believe that now, but it was just an honor and a humbling experience, and I'm glad I got the call."

Just like Burl Toler was in 1965, when he became the first African-American official in the NFL, Thomas is a trailblazer. What started nearly two decades ago when she accompanied her older brother to an officials meeting has brought her to football's biggest stage.

But Thomas contends that she never set out to become a pioneer. She grew up in Pascagoula, Mississippi, with two brothers who played football. Thomas played softball and basketball. She earned a basketball scholarship to the University of Mobile, where in three seasons she amassed 779 points, 411 rebounds, 108 assists and 192 steals, which ranks fifth in school history.

Thomas graduated in 1995 with a degree in communications. Not wanting to lose the camaraderie and competition sports had provided, she looked into becoming a football official. It was, as she said, life changing.