what could this be from? These pictures were taken in the attic. This was the only rafter that looked like this. When I probed it, it was like a powdery consistency.
Hard to tell for sure by the pics.
But based on your location it looks like subterranean termite, the damage goes with the grain of the wood.
It’s exposed/not closed so it does not appear active.
I don’t see any powdery stuff though.
<<MG>> State Lic Termite Operator #2446
I’m willing to bet the damage happened before the rafter was installed; many decades ago.
Based on some of the coloring of other wood members in the pictures it looks like there was a fire at one point.