If you are going to kill a bunch of prairie dogs, you can make a bait pile. Once it stinks a bit coyotes will come to get a free meal. If you have a "dead pile" around the ranch, that is even better. You don't trap at the pile--you figure out a travel route coming in like along the fenceline, then set the trap there.
If you've got but a couple prairie dogs (or skunks work better), you can find a wide open area in a field that you know coyotes run the edges of. Bury the dead skunk headdown with half its tail sticking out in the air, with a trap about 8" off the base with some kind of blocking on the back side. Coyotes love to eat dead skunks and prairie dogs.
If you're just going to trap the dog town itself, don't bother with dirt hole sets. Find the travel lanes that they come on, probably along a fence line, and set a flat set, step down, urine post, or something similar.
Also, coyotes travel in family groups a lot--always gang set. If it's worth one trap in that area, then it's worth a couple more.
