No hatch in North America incites as much frenzy as the emergence of Pteronarcys californicus, the giant stonefly (a.k.a. salmonfly, a nickname that comes from the orange color on the thorax), in the rivers of the Rockies. It's a season of gluttony that stretches from late spring to midsummer, with exceedingly bad table manners exhibited on one end of the fly line, and ecstasy or despair on the other. For the trout it's a matter of gobbling all they can stomach in the shortest time, because in any one stretch of river the hatch lasts no more than a few days. But a fisherman who possesses a sense of adventure and four good tires can nurture his own brand of madness for a month or more, hopscotching from river to river as the insects make their appearance.