I came across a couple of women driving a beater pickup at the crest of Weston. They had stopped to take in the view then the truck wouldn't restart and the battery was run down.
Out came my jumper cables and nope, wouldn't restart. They had filled the gas tank in Denver and the gauge read a full gas tank still. Poked around a few minutes and found the truck had dual tanks so flipped to the other tank. Varoom the truck started.
1. They didn't know the truck had dual fuel tanks.
2. The fuel gauge only indicated for one of the tanks.
I almost made it over Weston Pass in the winter. The deep ice finally got me. Had to dig out and go back. ;)