According to this story, three independent candidates for U.S. Senate have enough valid signatures in South Dakota. The latest entry is Clayton Walker, who submitted 3,500 signatures. The requirement was 3,171 signatures. Walker’s high validity rate is probably because he collected virtually all his signtures door-to-door. He estimates he knocked on 10,000 doors, almost entirely during winter, to get his 3,500 signatures. Much of the time, he worked while snow was falling, and he says many of his petition sheets were still wet when he submitted them.
This will be the first U.S. Senate election in South Dakota history since 1924 with more than two independent candidates on the ballot. Back in 1924, statewide independents only needed 200 signatures.