The term 'AH, WILDERNESS!' can be broken down into three crossword solutions: NAT (3 letters), ESSIE (5 letters), and THEPETRIFIEDFOREST (18 letters). NAT is an abbreviation for the National Park Service, which is responsible for the preservation of wilderness areas in the United States. ESSIE is a reference to the Essay on the Principle of Population, written by Thomas Malthus in 1798, which argued that population growth would outpace resources and lead to environmental degradation. Finally, THEPETRIFIEDFOREST is a reference to the Petrified Forest National Park in Arizona, which is home to some of the world's most spectacular petrified wood formations. Together, these three solutions represent the importance of preserving wilderness areas for future generations.