platforms. we begin with lilia luciano and a breaking point in a california beach battle. >> reporter: nestled along california's central coast is oceano dunes, eight miles of beautiful beach. but the scenic stretch of sand has gone from playground to battleground. more than a million off-roaders a year visit the only state park in california where vehicles can drive on the beach, pitting recreation against conservation. why is it important to be able to bring vehicles onto the sand? >> it's a magical, unique experience. >> the amount of traffic, the noise pollution, the destruction-- it's just-- it's too much. >> reporter: battle lines drawn in the sand by off-roaders, theo town of oceano, two state agencies, and conservationists fighting to protect endangered species, including the western snowy plover, and california's least tern. >> the vehicles disturb the birds.