Unconquerable majesty: how I fell for America's national parks

For more than 100 years, tourists and photographers have flocked to America's national parks. Tim Dowling salutes the spectacular lakes, canyons - and rangers

" America's national parks in pictures

Some years ago, my family and I paid a visit to the Rainbow Bridge national monument in Utah. It's a natural stone arch, roughly the same height as the Statue of Liberty, and so remote that it wasn't located by white people until 1909. It used to require a desert hike of several days to get to the bridge, but ever since the dam turned the Glen Canyon into Lake Powell, it's only a two-mile stroll from a convenient landing dock. When we arrived, no one was around, apart from a park ranger stationed on the path, waiting for us, ready to answer any questions we might have, and to ask us to refrain from walking under the arch, because it is a site of tremendous religious significance for several Native American tribes.

This federal employee standing in the middle of the desert - engaging, articulate, genial - seemed as much a monument as the bridge itself. I don't think I've ever met anyone who enjoyed his job so much. We took turns posing for photographs wearing his hat.