Bill, my guys are the same age and are playing up this year. Our region has changed over to grade designations, so my 12 year old was on the U15 roster (she's playing both with her U13 team and the U15s because their roster was slim), and the boys moved up with their coach from the past two years.
It's funny, our club is only going into its fifth year (my kids have played three), even though lax is huge in the mid-Atlantic. I played in high school, and it was well established then (in the 80s). On the other hand, my husband is from the DC metro area and they weren't playing lax, either... So maybe it was a pocket interest.
Hope you guys have fun with it, we certainly do! (I type as I get ready to walk out the door to begin day 1 of 5 on the field. :) )