I somehow got one bar on my Verizon phone on the summit but couldn't get a call out (or text). It drained the battery trying to find a cell which seems to be something every Verizon phone I've owned does. My advice is to leave it back at your car and look into the Spot II (that's on my personal "wish list"). Besides, I find not hearing or feeling obligated to a cell phone one of the joys of hiking.
