U.S. Scott 397, the 1 cent Panama-Pacific issue picturing Balboa paying the 1 cent post card rate. The cover was post marked on the Billings & Termopolis RPO route by the Railway Mail Service on December 26, 1913 and is addressed to Saskatoon, Canada. That RPO was only in operation from 1910-1914. The card pictures Dr. Gray's Hospital.
U.S. Scott 397 on 1913 Billings & Thermopolis RPO Post Card to Canada
Returns accepted for up to 30 days from the date of mailing, for any reason, as long as the item is returned in the same condition that it was sent.