Salmon Creek, 8 mi. w Rogerson, Twin Falls Co., Idaho. May 15. To move from one place to another). The scat are similar to those of maniculatus. Signs of Neotoma was abundant, but I failed to catch any. However, Swining caught two on a rocky outcropping about ½ mi NE of our camp. I saw some Porcupine workings in the willows and scat along the base of the cliffs. No other mammals were noted. I was fortunate enough to bag a White-throated Swift. They appear to be mating, judged by the aerial maneuvers the birds go through. Two – apparently pairs – birds flit here and there over the canyon and occasionally one of the birds would alight at and disappear into vertical crevices in the rocks. These place appear to be future nesting sites. The condition of the female indicated pre nesting condition. There are about a dozen birds using the first ½ mile of the canyon. Also took one Violet-green Swallow and two Cliff Swallows – the latter