Welcome to AP.
Yes there are. There is a dedicated airsoft field in Klamath Falls.
https://www.facebook.com/PhoenixCompanyAirsoftThere's an active field behind Laurel Hills Golf Course in Gold HIll, they play Saturday mornings IIRC.
There's this group:
https://www.facebook.com/profile.php?id=100003201945571http://soap.freeforums.org/If you want more info, the guys at the Rogue Military shop 541-476-0330 can help you.
There are other groups scattered around SO, those are just the few I know of.