[52] This passage shows clearly that the party was traveling the Sacramento relatively far above Suisun Bay and that therefore the entrance to the river could not have been by way of Threemile Slough above the head of Sherman I. Accounts by many later voyagers, as well as the existing condition of the terrain, indicate unequivocally that the oak trees begin, on ascending the river, no more than a mile or two below Rio Vista. The heavy oak stand with dense undergrowth and grapevines appears near the foot of Grand I. and continues thence up the river. Hence it is most probable that Abella entered the Sacramento R. at or near Tyler I., no farther downstream than Isleton. The population described in the text is much heavier than has been generally ascribed to these islands by modern students (cf. Schenck, 1926). [53] Foot of Grand I., where Steamboat Slough joins the main river. [54] He refers to the main stream of the Sacramento and Steamboat Slough plus the slough or channel which we cannot identify and through which he reached his present position below the foot of Grand I. The party was now not far from the site of Rio Vista. [55] The description fits the north bank of the river below Rio Vista: the bare rolling hills are the Montezuma Hills, the high hill of the Bolbones is Mt. Diablo, the plain is the flat area stretching north from Sherman I. all the way to Fairfield. The distance traveled was far less than 12 leagues but it is true that at about the halfway point the oaks and other river bank shrubbery fade out and the land becomes pure grassy pasture land. [56] Probably referring to the exploratory expedition of Ayala and Cañizares in 1776. Cañizares reached the vicinity of lower Sherman I., when he repeatedly ran aground and was forced to turn back. [57] The exact course of the expedition on the 27th and 28th is difficult to trace but in outline it is fairly clear. Priestley (1946, p. 108) says: "From the Ompines the navigators went through Nurse Slough and Montezuma Creek to a point one league east of Suisun." This is unlikely because one must navigate several miles of Montezuma Slough before arriving at Nurse Slough. The head of the latter is fully 8 mi. from Suisun. Furthermore, Abella says the "Yano de los Suisunes" (the plain of the Suisunes), not the town of Suisun.