Cogswell 1950 Iridoprocne bicolor 2 July 9. E. end Lake Tahoe, 6230 ft., El Dorado Co., Calif. - 30+ seen in 1/4 hrs. Spent on marsh just back from beach near Camp Richardson. They foraged low over the lake, rising over the strip of lodgepole pines along the beach, & then down again over the wide marshlands, by far the commonest swallow here. July 10. E. side Boca Res., 5580 ft., Nevada Co., Calif. - 2+ flying with Cliff & Barn Swallows over grassy swale & surrounding sagebrush country. Open Jeffrey pine forest (partly burned) is within a few hundred yards. July 19. E. end Lake Van Norden, 6780 ft., Placer Co., Calif. - about 20 flying over meadow and perching on wires near sheep corral. This is big increase over breeding population (see July 4). Several in juvenile plumage. July 30 only about 6 here today, as on previous dates since 19th. Aug. 1 at least 30, most of them near mouth of Castle Creek near W end of lake; perches utilized on wires crossing the creek-mouth & in nearby tall dead lodgepole pine. Aug. 3 [250] ft., 1/4 mi. N Donner Pass, Nevada Co., Calif. - 1 flew, [lattp.m.] over open slopes of granite boulders on Sierra crest in sagebrush. Aug. 6 E. side Boca Res. [see above] - several foraging over grass. Aug. 15 L. Van Norden, 6780 ft., Placer-Nevada Cos., Calif. 3+ (only!) seen in areas E & N of lake where common 2 wks. ago.