Browning; I have never hunted your part of the country, but have hunted yotes from East Texas through New Mexico up to Idaho and have found them to be very smart. Are you sure that the tracks that you are seeing are not dogs that are rangeing away from home at night for a roamp with other dogs. I talked to a local ranch hand just about 3 weeks ago that had to shoot his stock dog for killing calves. He was with a pack of dogs that belonged to local ranchers and was almost 10 miles from home. If hunting with a light at night is legal, I have found that to be productive when all else fails. Just keep the light pointed upward until you spot the glow of their eyes in the dim light from the very edge of the beam, then lower the beam and shoot before they spook from the bright beam.
You seem to be useing small bait peices to lure them in. Get a large bait and wrap a few strands of wire around it and tie it to the base of a tree or, drive a stake into the ground so as to anchor it and keep them from dragging it into the brush where they are unseen. Remember, that the key is always to get into the area undetected, and remain undetected until the shot is made. The animal should die without suspecting that a human is in the area. If you should make a kill, just sit tight and call for 4-5 minutes as his buddy is likely not far away and a double is a real possibility.