Hi Mathew - Glad you included the photos - they help for sure. A few questions - where are the pines - county or nearby town?  When did you first see the trees fading and turning that red / dead color? What kind of soil is on the site - sandy or heavy clay or other?  

It looks like bark beetles or longhorned woodboring beetles (like pine sawyer) colonized the dying or newly dead trees. That's why you see the small round exit holes left by the BBs. The larger squarish holes are where woodpeckers went after larvae  - probably the larger sawyer beetles. These are secondary insects - not attracted to and not successful when trees are healthy. They want stressed, dying or newly cut or broken trees. The drought in late summer and fall stressed a lot of trees - could have attracted the beetles but I think the trees were dying or dead before Sept.  

I'm wondering about HRD - the Heterobasidion Root Disease - that is affecting red pine stands in spots all around Michigan. Its a fungal pathogen that spreads via grafted roots, so you often see expanding circles of dead trees. You  might google that and see if the symptoms seem to match your stand.  There are other pests that affect red pine - pine root collar weevil is not uncommon - but that usually takes 4-6 years before a red pine dies.