(Steamer Zephyr). 1868 letter written on board tells of Ft. Benton (Montana) to Ft. Sully (Dakota) trip, cover is postmarked "Quin To St. Joe, R.P.O." with Pacific House, St. Joseph, Mo., corner card franked with 1867, 3¢ rose, F. grill (flaws), opened roughly at right, Fine, interesting early steamer/Railway Post Office connection. Estimate  $200 - 300. $0 (Image)