Pteleka 1943 June 15 2 mi E Hayfork, 2400 ft., Trinity Co., Calif. of Hayfork Creek (west of Hayfork) are covered with scattered bottomland forest of poplar and willow. Patches of chaparral, primarily tall chaparral, are evident on the eastern slopes of the basin. Gunnell's life-zone map indicates the Hayfork basin as Upper Sonoran, but on the basis of our brief observations, I think the area is better recognized as Transition. The forest to the south (below) is primarily of the yellow-pine-oak type. Such grassland and digger pine areas as are present appear to be expressions of edaphic factors rather than climatic factors. In the evening, we established camp 2 mi E of Hayfork, just east of the Big Creek-Hayfork Creek junction. The open woods surrounding our camp are dominated by yellow pine and gray oak. The ground cover consists of scattered shrubs of manzanita and Ceonothus, the open area covered with grasses and a variety of flowering annuals. Immediately to the south of camp is an area of dense, tall willows, which form the north border of an area along the north side of Hayfork Creek disturbed by placer mining.