This is an alternate starting point for the Upper Salt Daily run, and the Wilderness run, that lets you experience a couple extra rapids compared to starting at the traditional put-in.  Drive out of Globe on highway 60/77.  Drive down the Salt River Canyon, cross the bridge, and turn left on a dirt road.  Drive down the hill and turn left.  Drive along this road - in season, this road will go through the commercial guides operations, but just let them know you're a private boater and carry on.  You'll drive under the bridge, and pull up next to Baptism rapid.  Note that you can't actually leave a car at Baptism Rapid, so you'll need to unload your gear, then take your car back up the road a bit to park it under the bridge.