By definition, Wilderness Areas must be roadless and are for non-mechanized access. Roads are well-documented as detrimental to wildlife populations (1), and water quality (2). Since designation comes after most parts of the country have been settled, wilderness areas tend to be tracts of rougher landscape where few if any roads were ever built. Trail systems for hikers and horseback riders encourage access with less-damaging consequences.
Aldo Leopold also helped change prevailing ideas when as a young Yale graduate he worked for the Forest Service in New Mexico. It was through his documentation and persuasion that three-quarter million acres in the southern part of the state was administratively set aside by the agency as something called "wilderness" in 1924, the first time anywhere that wild lands were intentionally set aside to be left roadless. It took Congress another forty years to catch on.
However, most Americans know Leopold through his later writing, especially A Sand County Almanac published in 1949. Leopold describes life on his farm and surrounding areas with such depth of feeling that it has inspired others to follow his "land ethic", the idea that landscapes have merit in their own right and that even when farmed or otherwise utilized we should strive to live in some balance with those landscapes. For more on Leopold and some of his legacy, see the biographical film (3).
So on this anniversary year of the Wilderness Act, I intend to re-read Leopold, make a pilgrimage to our local Pecos Wilderness, do what I can to see public lands respected for our future, and be thankful.
(3) Aldo Leopold Green Fire trailer http://www.youtube.com/watch?v=iQED4YEMx9A