...seeing as you're in ohio, as am i, we've got a lot of good dead wood here.
good ol' elm. this stuff isn't really ready 'till the bark's comin' off.
osage orange (hedge apple). is never "over". worked a big one up that had been down for 8 years. you'd never know it.
locust, same shelf life as hedge.
sycamore seems to hold up well, also.
old cherry, red oak, birch, beech, been down awhile, take a cut at the base. junk there, junk everywhere. sometimes you can get up from the base a ways before it turns to crap.
walnut kinda goes punky from the outside in, for some reason. i've found it still has heat value if the dark "vein" is solid.
the old lift test. you buck a piece, you know what it should weigh. feels like balsa wood? probably is.
i cut a lotta dead wood, as you can tell. i maintain a lotta of the farms around here. now, i let my saw tell me. if it falls through, or even starts to, i move on. there's entirely too much of it to waste my time deciding if it's worth it or not.