I had a similar situation many years ago.
In my case I hit the near side shoulder blade. My situation was very similar to this.
I hit him at last light. After following a similar blood trail by flashlight I backed off and returned at daylight.
Trailed him to a bed, where I jumped him, about 200 yrs from the initial hit.
The bed looked identical to yours. What I see here is clotting type blood.
Anyhow, spent another 5 hours gridding and searching but did not recover the deer.
If you don't find him, take comfort that the hit may not be fatal.
The bone ridge at the back of the shoulder blade is virtually impenetrable.
For what its worth, my hit was at 20yds using a 125 grain thunderhead out of a 62 lb compound bow.
You are doing the right thing. Doing your best to recover him.
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