There are only ~580k registered voted in the state; fewer than 500k voted in the 2020 presidential election. A pool of 500 is basically 1 out of every 1000 voters, which is a solid sample.
I would still like to see what the cross-section is
Summer visitor, 500 registered voters (not necessarily South Dakotans) sorry, not buying it. 2922 figures 895,376 with the census corrections.