The Frisco issued passes based on need, seniority and merit. The user may have been restricted with regard to the trains he could ride or with regard to the territory where the pass was valid. There was an exception, i.e., "The White Pass", which was good on all trains, system-wide. They were issued but rarely, and for long, and faithful service or special meritorious service. Printed in gold on white linen, they were a reward to the faithful Frisco employee.
There is no telling what Mr Prewett did to deserve that pass. The White Pass was a big deal for a Frisco employee to possess.
Indeed, that must have been especially meritorious. Makes me wonder what "the rest of the story" would be on this one. Was the Frisco publishing any sort of employee magazines in 1937 or was that during the period where there was no publication? I've been contemplating making passes like these for my HO-scale operators, once I get some of the local guys over to do some switching in Olathe. I think I'll have to come up with a white pass as well when the circumstances warrant. Best Regards,