In the last couple of years a guy started the sage brush burning between Reno, NV and Carson City. It was a big deal in the newspapers that he had been shooting tracers. And he was facing criminal charges for starting the fire, and was going to be billed by the State of Nevada for a few hundred thousand dollars for putting the fire out. In addition private landowners were lining up for lost homes and other property damage.
Depending on the part of the country fires on military firing ranges from tracers are not uncommon.
As a shooter I was ducking my head. Every time somebody in the West starts a large fire with tracers we all take a hit. I know he would not want me on his jury.
I rather suspect that if you burned out somebody's ranch up in Salmon or torched the woods around Idaho City they might take it very unkindly.