The unassuming building shown in this photo with the nicely costumed re-enactors was a station on the Pony Express mail delivery route across Indian Territory to California.
The description on the back states:
ORIGINAL PONY EXPRESS STATION
From Cotton Seed Creek Near Bridgeport, Nebraska, moved 260 miles to the Harrold Warp Pioneer Village. Here can be seen 30,000 items in 22 buildings on 3 city blocks, showing man’s progress over the past 120 years.
132 Miles West of Lincoln, Nebr., on U. S. 6
— This card dates from the 1950s.