I find it some of the hardest photography and the most challenging photography I've ever done. It's a real challenge to work with the natural features and the natural light.

What I mean by photographing as a participant rather than observer is that I'm not only involved directly with some of the activities that I photograph, such as mountain climbing, but even when I'm not I have the philosophy that my mind and body are part of the natural world.

I think landscape photography in general is somewhat undervalued.

My first thought is always of light.

There is no question that photography has played a major role in the environmental movement.

A lot of people think that when you have grand scenery, such as you have in Yosemite, that photography must be easy.