The State Flag: Same as it ever was, except different.On this date, March 11, 1963, the Governor signed a bill providing that the South Dakota State Flag have the same emblem on both sides. Before that, the flag had differing emblems, which made it expensive to manufacture and hence, few people could afford to fly it. Sa-lute!

Source: http://www.state.sd.us/boa/CENTRALSUPPLY/Central Supply Catalog/History_SD_Flags.htm

It became increasingly evident by this time that the cost to manufacture a flag with a different emblem on each side was expensive to the degree that there were few South Dakota state flags in existence, and they were seldom flown. In the legislature of 1963, House Bill 503 was introduced by Representative William Sahr of Hughes County, enacted, and was approved by the Governor on March 11th.