In summer, many birders head for the higher country Buckhorn, the Wrightwood area, Mt. Baden-Powell, or to the San Bernardinos. In spring and fall the desert oases and coastal vagrant traps beckon.
Winter can be slow, bird-wise, and it's also rather cold.
Y et Charlton Flat offers very good birding at nearly any time of the year. In summer, there are many breeding and resident species. Though this area is too low for breeding Calliope Hummingbirds, they may be seen in migration. In fall and winter you can also find Red-breasted and often Williamson's Sapsuckers in the picnic area. Flat lies nearly in the middle of the San Gabriel Mountains, about 25 miles from the 210 Freeway along the Angeles Crest Highway.