The injury appears to be a few years old, as evidenced by the woundwood forming along the upper edges of the wound/gash.

I was not able to see any insects in the last photo.  Photos do not suggest that your ash tree has been infested by Emerald Ash Borer.     To date, EAB has been found in Colorado only in the city of Boulder.

It is possible that the sawdust and holes were caused by the Lilac-ash borer (LAB).   LAB damage is very common on ash trees, especially if they become stressed in any way.

Suggest you carefully try to remove any unattached bark -- without enlarging wound/gash.  Carefully smooth/sand the sawdust area.   Try to shape the bottom of the gash so that it sheds water (from snowmelt, rain, irrigation) rather than retaining it.    Apply any fungicide in the entire gash area 3 or 4 X per year.

Water the ash rooting area during dry warm snowless periods in winter.