[Williams Creek, British Columbia via California and OMC Route to Canada], cover to Aylmer, Canada, BC&VI 5c rose (#5) and 10c blue (#6) pair prepaid postage from Williams Creek tied by barred "10" cancels, blue "GPO British Columbia 10 July 1867" backstamp, the US 10c green (#68) paid the rate from US to Canada tied by cogwheel cancel in transit at San Francisco and with their Jul 19 (1867) postmark, arrival backstamp, some perfs on BC stamps scissors trimmed, image of reverse here, PF cert

ex Dale Lichtenstein and Walske (Image)