As we pulled onto the Marble Lane Bridge, a steel trestle built by a Dayton, Ohio, company in 1908, we realized why John Muir Laws (author of Sierra Birds: A Hiker's Guide, and research associate at the California Academy of Sciences) cites this as the best birding spot in the Northern Sierra. As it was midday, the bird activity in the Sierra Valley (the largest intermountain valley in the Sierra Nevada) was relatively quiet. And yet: hundreds of white-faced ibis pecking in the marshes; barn swallows and tree swallows looping above the water; one egret in flight; plus yellow-headed blackbirds, willets, coots, geese, (what I think was) a Swainson's hawk, and more.