So this one has me stumped. In almost twelve years of harvesting firewood around here, I don't recall ever getting a tree with dark heartwood like this. Thought it was silver maple before felling but never saw a silver maple that looked like this. Possibly elm? What I mainly pull from the area is red oak, white ash, beech, red and silver maple, and white birch.
To me it looks like red maple. There’s a lot of variation in those trees. I cut 3 this past week and each one looked different inside.
Im with the red maple crowd too. Bark and "spike" heals look typical to me for RM. The darker wood is "prerot" as said. A lot of the ones ive cut are hollow and/or rotting at the base. Common occurence here. Cool looking though and thanks for posting. let us know how good the "meat" is on the darker ones.