AFTER TRAVERSING A NATIONAL FOREST SERVICE ROAD LEAVES COLLECTED BETWEEN THE TRANSMISSION SKID PLATE AND THE EXHAUST SYSTEM. WHILE DRIVING AT INTERSTATE SPEEDS I WAS FLAGGED DOWN BY ANOTHER CAR TO INFORM ME THAT SPARKS WERE COMING FROM UNDER MY JEEP. LUCKILY THIS WAS AT NIGHT WHEN THE SPARKS COULD BE SEEN. I STOPPED THE VEHICLE AND IMMEDIATELY DISCHARGED MY FIRE EXTINGUISHER ON THE LEAVES. THIS ONLY SLOWED THE FIRE... COLD WATER FROM A ICE CHEST FINALLY FULLY EXTINGUISHED THE FIRE. THE DEBRIS WAS REMOVED AND THE AREA WAS INSPECTED WITH NO DAMAGE NOTED. I WAS ABLE TO CONTINUE ON MY TRIP. *TR