K Dixon 1947 Parus atricapillus June 17. Yellowstone River, 7 mi NE Glendive, 2000 ft, Dawson Co., Montana. Completely overcast; had rained during day; calm. While approaching nest previously located, I heard a "chickadee dee" call. Five minutes later, at 06:40 PM, I saw a chickadee approach the nest, enter, and leave, flying to the westward. 6 minutes later, a chickadee approached the nest from the north, landed on a nearby twig and entered, leaving shortly afterward and flying in direction from which it had come. A minute later another appeared from the south, entered the nest likewise with no calls and emerged, flying south. This bird carried no fecal sac; the other I could not see. The nest was located in a hollow formed by a rotten branch in an inclined trunk 4-10 feet above ground. Dead tree in grove of box elders June 18. Yellowstone River, 7 mi NE Glendive, 2000 ft, Dawson Co., Montana. Raining steadily all morning. I located the nest of a pair in the middle of box elder woods back from river, in area west of our camp. Nest was in a dead tree trunk (elm?) about 2 1/2 feet above ground. Both birds were bringing food to the nest, indicating that the young had hatched. I collected one of the adults which proved to be the ?. The adult birds gave no call when approaching the nest, but appeared reluctant