The Wailaki-Lassik boundary begins in the east at the head of the Mad River and runs west to the North Fork of the Eel, which it crosses at the mouth of Salt Creek. It follows Salt Creek for a short way and then goes west to Kekawaka Creek, which it follows to its mouth on the main Eel. It crosses the Eel here and then goes west to intersect the Sinkyone boundary at the East Branch of the South Fork of the Eel. The boundary as given here is identical with the one given by Merriam, except that he includes part of the drainage of the Mad within Wailaki territory whereas Kroeber does not. I have accepted Kroeber's version, because it is supported in a negative way by Goddard (1924), who fails to include any Mad River drainage in Pitch Wailaki territory. West of this area, Kroeber's boundary runs considerably north of Merriam's and of the boundary I have accepted. Merriam's line seems preferable because it is supported by Goddard and because Merriam's information is more specific than Kroeber's. According to the information of Merriam and Goddard, the Wailaki may be divided into three groups--the Eel River Wailaki, the North Fork Wailaki, and the Pitch Wailaki. The eastern group, the Pitch Wailaki, occupy the drainage of North Fork Eel River above Asbill Creek, Hulls Creek, and Casoose Creek. Their western boundary begins in the north on Salt Creek near its confluence with North Fork Eel. It runs south from this point along Salt Creek and beyond it, crossing the North Fork of the Eel just above the mouth of Asbill Creek and intersecting the Yuki-Wailaki line near Summit Valley. The northern border of the North Fork Wailaki begins in the west on the main Eel River at the mouth of Cottonwood Creek, about three miles north of the mouth of North Fork Eel, and runs from there eastward for about six miles, where it hits the western boundary of the Pitch Wailaki. The western boundary of the North Fork Wailaki is the main Eel River from the mouth of Cottonwood Creek south to the Yuki line near Bell Springs Railroad Station. The Kato-Wailaki line runs from the head of Blue Rock Creek in the east to the mouth of Hollow Tree Creek on the South Fork of the Eel in the west. This is Kroeber's version of the boundary. Merriam's version places the line somewhat south of this, beginning at Rattlesnake Creek in the west and going eastward south of Blue Rock Creek. Since I have ceded the drainage of Blue Rock Creek to the Yuki (see p. 160) in accordance with the views of Kroeber, I must, as a corollary, accept the northern boundary of the Kato as given by him.