Oregon State Parks offers more than 50 campgrounds across the state. While the majority of campgrounds accept reservations for campsites, some campgrounds are first-come, first-served seasonally or year-round. Note: reservations are accepted for all cabins, yurts, tepees and some special group facilities.
Here's a list of the first-come, first-served campgrounds:
Emigrant Springs (mix of first-come, first-served and reservable sites)
Farewell Bend (A Loop first-come, first-served. B and C Loops reservable)
Jasper Point Campground at Prineville Reservoir
Lake Owyhee (mix of first-come, first-served and reservable sites)
Smith Rock (special walk-in bivouac camping)