There was an execellent migration flight at Rock Creek Park, DC, this morning. Lots of small flocks of birds flying in, over, and through the trees, chasing eachother, etc. A few settled down long enough to be actually seen and identified! We were showing a Brit friend around so he was duly impressed. Best bird was an unbelievably cooperative Olive-Sided Flycatcher which flew into a rather low tree and sat for long minutes making sorties after insects, preening and giving looks at all its field marks to the five happy birders present! We even got good views of the white patch under the wing with the wing lifted. Other migrants included: Yellow-billed Cuckoo (3); Great Crested FC (2); Eastern Phoebe (3); Eastern Wood-pewee (4); Acadian Flycatcher (1); Empid sp. (1); Baltimore Oriole (2); Scarlet Tanager (2); Red-eyed Vireo (25); Blue-gray Gnatcatcher (30); 10 spp. of warbler (and there were a lot unidentified, zipping over): Black-and-White (5); Blackburnian (2); Chestnut- sided (3); Magnolia (1); Ovenbird (1); Blue-winged (2); Redstart (5); Yellow (1); Tennessee (1); Wormeating (2); Wood Thrush (1); Ruby-throated Hummingbird (8). Gail Mackiernan