Ona Beach is the day use beach access unit of Brian Booth State Park west of US 101, just north of milepost 149. There are paved parking, rest rooms, picnic tables, and the meandering mouth of Beaver Creek. Cross a foot-bridge over the creek for easy access 62B to the beach south of the creek's mouth. A less defined trail leads along the north shore of the creek for access past 62A to the beach to the north.
Ona Beach is a classic Lincoln County beach with light gray sands and occasional black rock outcroppings. To the south, houses are built atop eroding sandstone bluffs along the beach. I've read that one can hike south to Seal Rock along the beach and rocky shoreline, when the tides allow. To the north, there is a stretch of more dune-like land before the typical sandstone bluff reappears.
Pictures at Google Image Search.