To begin with, let's orient the image correctly:

Next, I searched all of Jim Forte's Post Office listings for Kansas with a town beginning with the letter "S" and containing a "k" in the middle. Although it's a stretch, the closest town name I came up with is "SNOKOMO", which was a rather obscure post office location open beginning in 1875 and closed by 1901. (At least the date on the manuscript cancel fits into that date window.)
Although it would appear the "town" no longer exists today by that name, Snokomo is referenced below:
Quote:
Snokomo, a hamlet in Wabaunsee county, is located 10 miles east of Alma, the county seat, and 12 miles north of Eskridge, the town from which it receives mail. Vera, on the Chicago, Rock Island & Pacific, 6 miles to the north, is the nearest railroad station.
As for the addressee, Mrs. Kate Elmer of Elmira, NY, I was able to find her obituary from 1911:

NOTE: The Kansas Historical Society Website further reflects the dates of operation of the Snokomo, Kansas post office as being established on 06/18/1875 and closed on 09/07/1881. The post office was reopened for a second time on 02/01/1886 and again closed for a second (and final) time on 05/15/1901.