Lone Ranch is a state beach located just North of Brookings on Highway 101. There is a large parking lot located about 50 yards from the water, with restrooms and picnic tables just above the beach.
I've been diving here several times, and it seems to be a popular place among divers. Personally, I'm not sure why, as it's always been all work and no play for me. Most divers head to the north side of the cove, along the rocks. It's shallow and surgy - maybe up to 40 feet deep. Vis hasn't been great the times I've been there - maybe up to 12 feet, which is still considered diveable here in Oregon. People spearfish and explore here.
To read an article from Rodale's Scuba Diving about diving this area, click here.