Yes - The road out of albany is FS 500 and takes you to Rob Roy (follow the signs), if you take that up the area I am talking about is at Rob Roy where T trail intersects it going north toward Libby Flats. That is where Elk Creek flows into Rob Roy. Take a right onto "T" trail and then take your first left on the FS road that parallels Elk Creek. You will see a bunch of spots there (get there early).
The other area that Coldfinger pointed out is the first point on the road that goes over Rob Roy (before the "official" Rob Roy campground and boat ramp). Turn right on that road and it will take you towards Cinnabar Park (the big open area where a you can camp as well).
You will find lots of spots, I don't know how often the 100' rule is enforced, there are some spots that seem to be within 100' that I see people use all the time.
If you want to play it completely safe - I think there are some good spots in the Rob Roy campground. You will have to pay the fee, but there are outhouses and trash dumpsters in that campground, but lots of traffic and boats going in and out of the lake during the day.
Don't sweat it too much, you will find a spot, and probably see a dozen more that you will want to try in the future. Holiday weekends get crowded, but on a normal weekend if you get up there in a reasonable time on Friday afternoon you should be able to find a spot that you like.