Thanks for all the replies! Let me answer a few;
Wind direction: Yes I am playing the wind direction at the sets. This particular night there was no wind.
Location: These sets are at road crossings of some sort (creek crossings, etc.). I grew up here and know where they travel and their funnel areas, The traps are set on heavy sign, as you can see from the tracks. However, this is open enough country that their travel route is never exactly the same, unless heavy snow is introduced. In that scenario, I go to snares. If I can get them within a few feet of my sets as I have here, I believe I have done my job as far as location. From there I have to get them AT the set.
Visual appeal: There is some there, perhaps I need to go bigger. In the pictures, it has a thin layer of fresh snow so you can't see it. There are charred wood, rocks, and large cow bones. Some are just dirt holes with an existing sagebrush as backing. There was food bait, gland lure, and fox urine at each set. There are two traps per location.

I have walked miles and miles following coyote trails trying to determine not just where they are travelling, but WHY they choose those routes. Now that I am confident on locations, maybe I could try some mock sets this spring/summer to test out some baits???

My suspicion is that they DO know those sets are there. A single coyote wandered through there a week before, but again, paid no attention to the sets. From your replies, my next attempt will include more visual appeal, and different (more subtle) smells. I will also try some straight urine post sets, never done that before it will take some research. Might try some big obvious hay sets in the middle of a hay meadow.

Pretty sure most of us have had scenes and experiences like the OP. The coyotes are always teaching the trapper. Lot of good advise already presented. I think a lot of trappers experience a lot of frustrations when they see tracks and marking around their sets. I certainly have. Gotta put those frustrations to the side and see what is there that can help you to understand a bigger picture. I get excited for most snows we have around here. Doesn't improve the conditions for trapping, it does improve conditions for me to learn and actually see what may be going on. The more you understand about the animal being pursued, the greater the chance for success. A lot of the responses you got are the experiences of the experienced. Well worth retaining and applying.

I know a lot of trappers plant their trap, and then watch it for weeks throughout a season, then, when the set connects, weeks later, they are satisfied that their sets work. They do. Not saying they don't. Just seems like a lot of checking, looking at empty sets, wondering why, and getting frustrated. Our coyotes pass through an area every 3-7 days usually. If they walk by my sets without working them. I add something. A smell, a different set, something. The biggest issue I've found for myself has been..
1) using bait when they have plenty to eat
2) not being on location
3) using the same smells at all or almost all sets, or not changing up from season to season
4) not being on location

You recognize McDeath by the golden arches. My bet is, coyotes recognize a good spot to look for a meal visually too. Most reading this post will recognize that pile of rocks as the golden arches, AND, they know to set it with multiple traps. Lot of trapping is about percentages. Improve your odds by planting more steel. Trappers that take a lot of fur, generally set a lot of traps.

I can't say I've got it figured out, but I'm learning, and for me, that is a big part of trapping. Gives me the chance to see, understand, and interact with nature.

^^^Excellent Post^^^

On logging roads I've had some success with chumming. I mix deer liver blood with water and some glycerin in a squirt bottle and just shoot a stream across the road. Not a lot, just a little.