The only time camping is allowed above treeline is winter, and even then there are guidelines.
Here is an encapsulated review of camping guidelines, follow the links for more info:
"LIVE FREE OR DIE...DEATH IS NOT THE WORST OF ALL EVILS." Gen. John Stark. "by reason of much foule weather and Extreme Bad Woods to travel in..." From the letter of my Great Uncle, Samuel Willard (accompanied by my grandfather Henry), to Governor Dummer on August 16, 1725, explaining the reason for his return, being instructed to "range all the country", of the Wawobadenik (White Mountains) July 19-August 16, 1725. I am a 13th generation New Englander and proud of it.