A historical event happened near here. Here is the story:
During the late afternoon and early evening hours of 23 July 2010, thunderstorms developed over portions of central South Dakota. Several storms quickly became severe in an environment favorable for supercell thunderstorms. In particular, one very strong supercell thunderstorm moved southeastward across portions of Stanley, Jones, and Lyman counties. One of the hardest hit locations was the community of Vivian, South Dakota, where extremely large hail, destructive winds to 80 mph, and a brief tornado were reported.
A record setting hailstone was ultimately discovered in Vivian, measuring 8.0 inches in diameter, 18.625 inches in circumference, and weighing in at an amazing 1.9375 pounds!! This hailstone broke the previous United States hail size record for diameter (7.0 inches - 22 June 2003 in Aurora, NE) and weight (1.67 pounds - 3 September 1970 in Coffeyvile, KS). The Aurora, Nebraska hailstone will retain the record for circumference (18.75 inches).
The hailstone's official record dimensions were as of the time personnel from the NWS in Aberdeen first observed and measured it. The stone did shrink considerably (melting and sublimation) between impact and when it was first measured by NWS personnel due in part to a power outgage at the residence of the individual who found the stone. It should also be noted that many other stones with diameters exceeding 6 inches were also noted during the storm survey!
What was I doing: I was driving through the area that day enroute to Pierre to go diving. We watched the big storm coming at us and stopped at the truck stop in Vivian for a minute and thought about it. We decided to make a run for it to Pierre. We just got a few rain drops on the car - we missed it by minutes. When we came back through the area two days later there were a lot of totalled cars and trucks and buildings.
Park in any of the parking areas and then make you way south through the tall grasses to the intersection of the fences and the cache.