_Breeding range._--The black-throated gray warbler breeds =north= to southwestern British Columbia (Hagensborg and Lillooet). =East= to southwestern British Columbia (Lillooet and Chilliwack); western Washington (Bellingham and Leavenworth); central northern Oregon (The Dalles); possibly southwestern Idaho (Riddle); southwestern Wyoming, possibly (Mountain); western and southern Colorado (probably Escalante Hills, Coventry, and the Culebra Range); central New Mexico (Santa Fe); and northeastern Sonora (San Luis Mountains). =South= to northeastern Sonora (San Luis Mountains); southeastern to north-central Arizona (Huachuca Mountains, Santa Rita Mountains, Santa Catalina Mountains, and Bill Williams Mountain); and northeastern Baja California (Sierra San Pedro Mártir). =West= to northern Baja California (Sierra San Pedro Mártir); western California (San Jacinto Mountains, Glendora, Santa Lucia Peak, and Lakeport); western Oregon (Kirby, Coos Bay, Corvallis, and Portland); western Washington (Spirit Lake and Shelton); and southwestern British Columbia (Victoria, Stuart Island, and Hagensborg). _Winter range._--The principal winter home of the black-throated gray warbler is in western Mexico. It is found in winter =north= to extreme southern Arizona (Yuma, occasionally in the Baboquivari Mountains, and Tucson). =East= to southeastern Arizona (Tucson); eastern Sonora (Tesia and Alamos); southwestern Durango (Chacala); northern Michoacán (Patambán); Mexico (city of Mexico); and central Oaxaca (Oaxaca). =South= to central Oaxaca. =West= to western Oaxaca (La Parada); Guerrero (Chilpancingo); western Michoacán (Los Reyes); southern Sinaloa (Escuinapa and Mazatlán); southern Baja California (Victoria Mountains and San José del Rancho); and southwestern Arizona (Yuma). It has also been found at this season casually, south to Dueñas, Guatemala, and north to Pasadena and Eureka, Calif., and Cameron County, Tex. _Migration._--Early dates of spring arrival are: New Mexico--Cooney, April 6. Arizona--Santa Rita Mountains, March 21. California--Grass Valley, March 24. Oregon--Portland, April 14. Washington--Tacoma, April 10. British Columbia--Chilliwack, April 16. Late dates of fall departure are: British Columbia--Courtenay, September 7. Washington--Yakima, October 27. Oregon--Eugene, October 11. California--Diablo, November 11. Arizona--Phoenix, November 8. _Casual records._--A black-throated gray warbler was picked up dead at Lenox, Mass., on December 8, 1923. A specimen was collected at Ithaca, N. Y., on November 15, 1936. On December 8, 1941, an individual was observed on Bull's Island, S. C.; and from December 26, 1942, to January 5, 1943, one was under observation at Miami, Fla. _Egg dates._--Arizona: 12 records, May 4 to June 19; 7 records, May 17 to 26. California: 32 records, May 1 to July 3; 18 records, May 20 to June 10, indicating the height of the season. Washington: 8 records, May 29 to June 28; 5 records, June 5 to 23 (Harris).