1: You can find this phone on the rooftop of the Crazy Moose Inn. To reach it, find the forklift behind the inn and use to reach the roof. Open your Profiler to find the phone beside the steel railing.
2: The next Burner Phone is found in the area of the trailer park. Find the blue colored house and climb to the roof. You'll find the phone on the railing.
3: The last Burner Phone in Pawnee is located inside the fenced yard behind the Fish and Chips restaurant. Go through the gate and open the shutters to the shed in the corner of the yard to find the phone.