NEEDLES, CA — Oregon native Daniel Price thought he was making a quick pit stop for gas and a restroom on his long drive through the California desert, but instead found himself in a quiet, humiliating standoff Thursday morning when the gas station clerk—without saying a word—lifted his arm and pointed to a bright yellow sign taped to the counter that read in all-caps: “PORTA POTTY OUTSIDE.” “He didn’t speak. Not even a nod,” said Price, who stood frozen in place for several seconds. “Just...