"I think all of us -- dad, me, my brother -- recognized a window of opportunity in which our flexibility as freelancers overlapped with dad's entrance into the golden years of being both retired and fit," says David Hanson. "Plus, it felt like dad and I had some things to figure out. Our differences weren't just that he liked park lodges and I preferred remote bivy sites." For the past five years, David's father, Scott, has visited a cluster of National Parks. And every year, David and his brother take turns accompanying him. Today, we travel with David and his father to Carlsbad Caverns, Guadalupe Mountains and Big Bend in search of two of the greatest gifts our public lands give us: family time and common ground. You can find David's writing, photos and video at: davidhandson3.com