Lot
558 
Mountain City K.T., March 2nd, manuscript postmark on 3¢ red (U27) buff Star Die entire canceled by manuscript "X" to Warsaw Ill., Very Fine, this postmark shows the "K.T." Kansas Territory designation two days after creation of Colorado Territory, ex-Meroni.Estimate $1,000 - 1,500.
By 1860, prospectors had proven the existence of profitable deposits of gold and settlement was rapidly fanning out westward into the mountains. Thirty miles to the west of Denver City, placer and lode mining on the headwaters of Clear Creek led to the establishment of post offices at Mountain City and Missouri City.
Realized: $750
Lot
559
Mountain City K.T., Sept. 22, 1860, manuscript postmark on 3¢ red (U10) buff Nesbitt entire to Kensington Conn., indicia showing second albino impression; cover with rough opening at right, otherwise Very Fine and rare Kansas Territory use, ex-Bauer.Estimate $750 - 1,000.
Mountain City in Gilpin County was one of the richest mining discoveries on the site known as "Gregory Diggings". The Post Office opened on January 17, 1860 while in the Kansas Territory. The office handled thousands of letters, and in October 1869 name changed to Central City.