I lost in the lottery in Utah a couple of weeks back. Travelling with a group of journalists, I attended the Wave lottery in Kanab. Each day, 10 hiking permits are handed out, allowing access to the Wave — one of the many stunning rock formations in Southern Utah.

Bad luck for us (though we went on to have a fabulous day canyoning down the Huntress — I'll write more on that later), but the lottery struck me as a terrific way to place value on your natural assets, and to protect them.

We should do the same for the Tongariro Crossing — our stunning 19km tramp sometimes looks like an extended queue, so crowded is the path. About 20,000 walked it in 1992, closer to 120,000 will do it this year.

I reckon 150 passes a day should do it.