The validity of this figure can be subjected to a check through comparison by area. This method cannot be expected to show up minor or secondary errors but it will bring to light any fundamental or serious discrepancies. We may block out four major regions: the Kaweah-Tulare Lake, the Kings River, the Merced River, and the segment between the Merced and the Kings. Each of these represents fundamentally the same type of environment, i.e., a rough strip extending southwest to northeast, beginning with the lakes and sloughs of the central valley axis, passing across the valley floor to the foothills, and reaching ultimately the middle altitudes of the Sierra Nevada. Four cross sections are thus obtained, differing in width but fairly uniformly including the habitats represented. It should be noted that the water surface of Lake Tulare as it existed in 1860 has been deducted from the area of the Kaweah-Tulare region; also that the two northern regions include a relatively greater expanse of uninhabitable mountain territory than do the two southern regions. The western boundary has been drawn along a line approximately five miles west of the San Joaquin River and the prolongation of its axis toward the lake. The westward extension of the Tachi toward Coalinga had to be neglected since there are no clear tribal boundaries in this area. The number of square miles was computed by township lines and the error of estimate must be considered at least plus or minus 20 per cent. The results follow: Population Area density Region (sq. mi.) Population per sq. mi. ______ _________ __________ ___________ Kaweah-Tulare 1,880 14,100 7.12 Kings 1,530 9,100 5.85 Merced 1,400 3,500 2.50 Mariposa-San Joaquin 3,760 19,000 5.05