James Lark went to Pine View, which is not in Hurricane. I was told by someone who would know that the best high school basketball player ever from Washington County was Brad Garrett. He played Juco ball in Idaho and was recruited by Kansas, Oklahoma State and BYU. He ended up at Oklahoma State. They went to the Maui Invitational (or another Hawaii tournament, I don't recall for sure which). He injured his shoulder while body surfing and it ended his college basketball career.
His parents live in my ward. (No, they weren't my source for best ever from Washington County). Bill Self was in their home on a recruiting visit. That's still a little hard for me to believe even though it's true.