Editor’s Note: “ My Happy Place ,” a CNN Original Series following celebrities on deeply personal journeys, airs Sundays at 10 p.m. ET/PT. CNN also tapped correspondents to share their happy places. Bill Weir feels a world away in Buckskin Gulch in Utah. CNN  —  At first glance, the desert landscape of Southern Utah seems like a sweeping, sun-baked canvas — wide open and endless. But tucked deep within its sandstone folds are narrow slivers of magic: slot canyons, sculpted over millennia by