I'm not directly familiar with lacrosse in Asheville, but since no one else has responded, I did a web search and came up with the
Asheville Lacrosse Club. I would suggest contacting them as a start.
This is younger than you asked for, but I also found
Peak Lacrosse for boys age 5-14.
Christ School, in Arden, is a private boarding and day school for boys in grades 8-12. They have what appears to be a strong lacrosse program.
You may have found these and more already by Googling, but I felt bad that no one replied to your question.