When we showed up to pick up our ATV, they inform us that since we booked through Viator, they have to charge us extra $130 for gas (not expected - not mentioned before), also make sure that you specify if you wish to go for a great views or hard playing. After all we had a great time and will rent again, but direct from the shop and request direction to the trails of our choice.
Machines are great, people very friendly and knowledgeable.