Poets Karla K. Morton and Alan Birkelbach began this journey to celebrate our national parks' one hundredth anniversary, but for these two poets the sojourns quickly became something greater than that. In their words, "As humans we have this tendency to look at a piece of land and see real estate. But] when concrete covers all our natural spaces, not only do we lose earth's creatures, we also lose the great teacher of our souls. You cannot sit...