I can say with certainty that I've seen adults play in Sewickley/Sportrak and at Tri county. Adult games are usually later in evening. Ie: u8, u10 might play around 5, 6, etc up to my nephew currently on a u19 team last night played at 9:20.
PA West does have adult outdoor leagues as well. Spring runs April to june; fall runs September to end of October. I don't deal with those but I have a couple friends that play on the over 40 teams.