One of our earlier halts was at an alluvial fan in Horshoe Park. The fan was created only in 1982 (15 July), when a dam high above, Lawn Lake Dam, suddenly failed. It is calculated that the lake was emptied of its 830,000 cubic metres of water within a minute. The resulting flash flood scoured out a gully, created the alluvial fan, rushed down the valley, killed three people (campers), smashed through a second dam, and created $31 million in damage to Estes Park. All this may have happened thirty years ago but the impressive scars on the landscape still seem very fresh. I find such breaking dam episodes slightly disconcerting. I was brought up on the tale of The Dambusters, of course, and as a child was deeply impressed by Guy Gibson’s account of looking down and seeing a car’s headlights extinguished as the desperately speeding car was overtaken by a wall of water. This fear of failing dams was compounded in 1980 when, on our way to Cortina d’Ampezzo, my architect host pointed to the Vajont Dam high above, responsible for the deaths of over 2,000 people in 1962. And I confess that I never felt entirely comfortable when camping just beneath the Bious-Artigues dam at the Pic du Midi d’Ossau…