As Ceciah Valero stood in the tunnel at Championship Soccer Stadium in Irvine, Calif., cards in her pocket and whistle in hand, she found it hard to sell herself on the idea that this was just another game. Refereeing was a natural fit once a knee injury ended her playing career at Santiago Canyon College. She had waited several years before stepping into the middle, reluctant to do so until she had full confidence in herself. But she was good at it, and worked her way up through the semi-pro leagues and the highly charged amateur scene of Southern California.



On that evening in June, as Valero stood waiting next to three other women in green refereeing kits and players from Orange County SC and Tulsa Roughnecks lined up behind them, things felt different. It didn’t help that people were coming up to take pictures with them, or that many of the 3,046 fans in attendance had been told that they were about to witness the first all-female refereeing squad in charge of a USL...