No problem Sherrie! I knew the age because I've come into contact with both the older and newer RC cola bottles, and was told the diamond pattern was from around the 1960's
The numbers on the bottom can indicate age. The most common age indicating symbol is the owens glass co mark. It often has 2 numbers, with the latter being the date. Yours doesn't appear to be made by owens glass co so it would be hard to hone in on the specific year it was made. As far as the desert location, back then trash was handled in the "out of sight, out of mind" attitude. So it is possible it was dumped there by a nearby city and there's more waiting to be found.