Never hunted them in SD, but have the Yellow-bellied and Hoary over many years in MT, WY, ID, UT, AZ, NV and CA.
Learning to recognize their preferred habitat is a start for finding them. But that habitat in the west can vary from rocky agricultural field borders to meadows (parkways) bordering wooded or forested areas to windswept rocky talus slopes up to alpine rock gardens above treeline. At what elevation is somewhat depending on latitude, can be near sea level far north, about 6,000' to well above 10,000' in the Rockies, and I know where a fairly strong population is at only 4,000 in SW UT. Latitude also somewhat dictates which and how many months a year they are above ground and active. Generally longest is May to September... or less depending on the year and latitude.
Personally I prefer the alpine habitats or cross canyon shots on rocky talus slopes myself, but have also found some unlikely lower elevation farm field borders that produced a lot of RC's.
Half the fun is finding them, and don't forget to leave some for seed in each population you find, then "rest" that spot for 2-3 years before shooting it again.
