It is a great book but not for everyone as it is written in a different style than most non-fiction books, typical MacLean style. I guess you found the description of burns to be gross, though they represent only part of the book as a whole. The description of how small blazes turn into infernos is what really sets the book apart. I also found the exploration of the two survivors lives afterwards as very interesting. My Grandmother was a secretary for the Forest Service in Missoula when this happened and she remembered the incident very well. At the time it was a shocking loss of life, and to this day would still be, but in the last 60 years has been overshadowed by even bigger tragedies in wildland fire fighting.
I once took 'Helter Skelter' to scout camp. It seems that you would prefer something more nature based : )