Roads are iffy in this entire area. Sunstone is a variety of plagioclase feldspar, and it's found in only a few places in the world, and only two in Oregon. The best place in the world to find colored sunstone is in the desert north of Plush. Read all about it in Gem Trails. You can get clear to straw, weak schiller, and not much else there.
Small stones are the norm.
If all you want is tumbling material, go here. There are two mines that allow fee digging. The first on the road in is Teddy Ridge. Some people have found nice schillers and reds here. They are the exception rather than the norm.