I purchased 9½ x 6 inch three subject notebook to take notes about things that happened along our trip; a log if you will. I put a ball-point pen in the spiral binder to insure that I would always have something to write with. I recorded the "where to" departure/arrival dates and times, gas purchased/mileage, and just about anything I wanted to remember.Another record was made of our trip. I used a credit card to pay for everything I could. That way we did not need to carry a large sum of cash. The credit card invoice is a good record of where we were and when.
Most of the gas pumps I saw and used were "pay at the pump"; the kind that gives you a printed receipt. Even in Oregon they have those, but you better not touch that pump! Oregon does not allow self service gas stations. All of the receipts where put in a folder in my briefcase.
All of these records were used to build the web page about our trip.