It seems winter never wants to leave South Dakota. On this date, April 30, 1967, a major blizzard hit West River, one of the latest on record. So, maybe no more blizzards as a TBDISDH for a while.
Source: http://www.crh.noaa.gov/fsd/?n=fsdtrivia04
April 30th, and May 1st, 1967 a late season blizzard swept across the northern plains. One of the latest major storms on record for the state began late on the April 30th and continue into the first day of May. Snowfall across western South Dakota was generally in the 5 to 12 inch range with 16" at Lemmon and 30" in the northern Black Hills. Winds of 40 to 50 mph reduced visibilities to near zero and piled the snow into 4 to 5 foot drifts. Livestock losses were estimated at around 5% from the storm.
Eastern South Dakota, Southwest Minnesota, and Northwest Iowa only received light snow.