We've been hiking in Yosemite National Park now for several days. Yosemite Falls, Bridalveil Falls and El Capitan have been world class. Today, my family and I are going to tackle Half Dome, one of the great granite rock formations in Yosemite Valley.

We appear to have lucked out with the weather-beautiful, sunny and low humidity. There is no need to dress in layers today. The visitor center has been consulted, the trail highlighted in green magic marker, sandwiches packed and camera batteries charged. We're ready to go.