(Ahem) A note from a man that has possibly set more military firing ranges on fire than anyone since Mikhail Kalashnikov-
A tracer bullet has a tail of very hot flame that extends out of the rear of the bullet during flight. This can be a foot or more in length. The bright color you see if flight is the flame.
If your bullet hits something prior to "tracer burnout" distance, the fire is still burning. Meaning put one into the woods in dry season, and Smokey D. Bear will come whack the crap out of you with his shovel.
THEN he will present you with the bill for the COST of putting out that forest fire. Yes, you are legally liable for the cost of putting out a fire you start.
Tracers are legal in MOST states, but not all- so check your state laws, exercise extreme caution when shooting.
BTW, my military ranges had a large firebreak plowed around the perimeter, so that when we lit one up, did not burn down the rest of Ft. Mildew. Does your shooting area have anything similar?