Steve,
Great sign. It's like some in Yosemite like at the top of Yosemite Falls. "Don't go in the water or you will die" They still do. Too much verbiage. It seems if a sigh has more that two words it doesn't get read. I would think three signs. One just on the spur trail to the peak "PEAK"
One just down toward the portal "YOUR CAR"
and one just on the JMT "PACIFIC OCEAN". A bit on the light side perhaps but it amazing how people won't read or heed anything with more than a few letters.