1 tank of gas at park = $80 <--- might use less but I would rather calculate too much gas
I think you would use a lot less. When we were at River Rock we rode all day Saturday and a few hours Sunday and I don’t think I used even a 1/4 tank of gas. I would say to play it "safe" estimate half a tank while at the park.
Yeah, I can get to RR, ride all day, and get home on half a tank. ;D