Gasoline is one of the few tax cash cows that can't be smuggled out of a Native Reserve. Farmers are the only citizens legally allowed to have gas pumps on their own privately owned land.
Besides increasing tax revenue, increased gasoline prices discourage unnecessary travel. One of my worst memories of childhood is having to be a part of the 'Sunday afternoon drive'; my father would pile everyone into the station wagon, then he'd drive on highways for a few hours, not going anywhere in particular, not stopping anywhere, just driving around. If he was asked for the purpose of the excursion, his answer would be "That's what people do". It was worse than having to watch the slide show from the parent's vacation trip.
Besides increasing tax revenue, increased gasoline prices discourage unnecessary travel. One of my worst memories of childhood is having to be a part of the 'Sunday afternoon drive'; my father would pile everyone into the station wagon, then he'd drive on highways for a few hours, not going anywhere in particular, not stopping anywhere, just driving around. If he was asked for the purpose of the excursion, his answer would be "That's what people do". It was worse than having to watch the slide show from the parent's vacation trip.