Very interesting. I didn't think cougars ate carrion. Maybe just an old wive's myth on my part. Certainly a healthy cat.
they will scavenge fresh meat then they get the chance
It's not a hard and fast rule but IME cougars generally don't eat stuff that they haven't killed. There are exceptions, obviously.
I shot a buck one evening and did not find it till the next morning, several hundred yards beyond where I had tracked it the evening before. It snowed an inch during the night and after the snow a cougar had come on the blood trail, followed it to the deer and apparently leaned over to sniff it but did not touch it. Fresh kill, no human scent. I was surprised on that one that it did not eat some of the deer. 
I assume you are correct that the elk died naturally, but is there any chance that the lion killed the elk and came back later to feed? Sometimes the kill marks leave little external sign. We have tracked cougars to a kill which it left without eating any, and then it came back hours later or the next day and started eating. They break the patterns I expect from them often enough to keep me humble!
GREAT pics BTW!
I suppose he could have killed this elk, when we found it one of the front shoulders was eaten and about 18 inches of the rib cage was exposed, we looked around and did not see any bite marks on the back of the neck but did not look at the underside. I thought that cougars would alway cover there kill.
Re kill wounds: Thanks for the added info. I got curious on one large blacktail buck obviously killed by a cougar and partly eaten, so I examined and skinned to find out how he killed it. No sign that I found showing externally. By skinning the neck up to the skull we found where the large cougar had bitten the buck on the back of the neck just below the skull, severing the spine and spinal cord between the first and second vertebrae. Once I found the tooth holes then I could part the hair and locate them from outside but otherwise had not seen them.
Re covering: I've found several kills that have not been covered, and a couple where the cougar dragged the dead deer under low overhanging limbs in snow but otherwise did not cover it. Small sample. I'd be curious to hear what other lion hunters have found. Pics from California and SW show covered cougar kills but I've found more up this way that are not covered.
I picked up a road kill mulie once while on my way out to elk camp. I wasn't so sure about eating it myself, but I figured I'd at least take the hide off and brain tan it. When we got to camp and opened the back of the truck, the smell (even though it was below freezing) that came out assured me we would definitely NOT be using any part of that deer. Dragged it into the woods about 150 yds downwind of camp, made dinner, went to bed. Hunted the next morning. On our way back we found fresh cat tracks of a big male headed right towards our camp. He had grabbed that stinky mess, walked it 100 yds downhill, then feasted on the internals and right hindquarter. He buried the rest really well. We followed his exit trail a fair distance, found maybe 8 puke piles that cumulatively came to about 5 pounds of undigested flesh. That was interesting.
Spoke with an area WDFW bio a month later, one who runs cougar studies. They said, "Yeah, we use road kill venison as bait all the time. Never fails to bring them in. In fact, the stinkier, the better."
