The most birds you're likely to see at one and the same time would be two adults acccompanied by fledglings. Other than this situation, if you see a flock of birds during March through May you're not looking at Golden-cheeked Warblers. During the molting period, expect birds to look pretty ragged. Feather patterns will be more obscure than those illustrated in the field guides. By the end of July, almost all Golden-cheeked Warblers have assumed winter plumage and left for the highlands of southern Mexico and northern Central America.
Young birds are usually the last to go.
The Travis Audubon Society's Wildlife Sanctuary has three trail systems. It's fairly easy, though it has lots of loose, sometimes slippery rocks. A few stretches are fairly steep. Warblers occur in wooded areas along all three trail systems. An update in the spring of 2000 will give information on particularly reliable spots for singing males.