In this branch of the river, as in all the others which we have seen, we observed that when the tide rises, the water in some places comes up to a height of a vara and a half, and this is quite to be expected on account of the flatness of the land and the thrust of the sea through the Carquinez Strait. The channel of the river over which we traveled today has a width of a quarter of a league and in places somewhat more. We cruised today somewhere near eight hours, four of them with a fresh breeze, and we measured about eighteen leagues, all to the east, with the river turning now and again to the northeast. We stopped at an island which has trees of some thickness but which is choked with underbrush, and it is evidently submerged during floods. A little before reaching this island the river divides into two branches. From the mouth some alders are visible at half a league distance to the left. This is the entrance which should be taken at this island. The place where we stopped was recognized as a fishing location of the Ompines, for there were signs of campfires.[28] _18th day._ We set out from this island at seven o'clock in the morning, and went back half a league so as to enter the previously mentioned river mouth (although it seems to me that it is not necessary to go back, but rather to follow the same entrance for we afterwards saw that they [the two river mouths] joined each other, a thing which even the guide had not yet noticed). We traveled about seven leagues to the east, with a fresh north wind. The river makes some turns at about one-quarter of the seven-league distance and forms another island with the opening[29] where we slept. This is why I said that it is not necessary to turn back. Everything is tule swamp on each side, with an occasional bush. The channel, as has been stated, is about a quarter of a league wide. At noon we [stopped and] landed in a swamp. Here the river widens considerably and there is another opening, which, although somewhat concealed, communicates with the River of the North.[30] The latter goes up to the left and is the one we took on the 24th on the down trip.