I took up the watch after Czaplak, Haffner and Powell left at 2PM and  
searched both sides of the canal until 3:30 without seeing the  
Townsend's Warbler.  Along the way I spotted the following birds:

Palm Warbler
Hermit Thrush
Brown Creeper
Dark-eyed Junco
Golden-crowned Kinglet
Red-bellied Woodpecker
Downey Woodpecker
Northern Flicker
Eastern Phoebe
Turkey Vulture
Northern Cardinal

Wallace Kornack
Washington, DC