I was mowing some tall ragweed along a fence line, approaching a large dead hackberry tree. When I got near the tree the tractor suddenly veered right into the tree. The right front tire had hit a fallen branch in the weeds and followed the branch right into the trunk. When the loader bucket hit the trunk the impact knocked a 200 lb branch from above and it crashed down onto the tractor, narrowly missing my head. The branch hit the vertical muffler and crushed it some, plus bent the steering wheel and rear fender. I thought about all the different kinds of injuries I could have had, from smashed arm bones to broken neck, then thanked God for sparing me. Then I hefted the branch off of Old Blue, straightened the bent steering wheel, and kept on mowing.