The off road area for 4x4s is very small. The SVRA is a large area and great for exploring However the 4x4 area is probably 5 acres.
You will never run out of things to do at Carnegie I don't know how many acres there are but I think it's over 1000 acres? I've been there a few times and I don't think I've seen the whole place it'll be worth going. There are 1300 acres.
Thanks! Your answer is awaiting moderation.