In the years following the Cuevas episode numerous expeditions were sent out which opened up the interior of California. Most of these are more appropriate to a consideration of the interior valleys than to a survey of the coast ranges to the east of San Francisco Bay. Two, however, contain sufficient pertinent material to warrant their citation. They are the first expeditions by Father Fray José Viader in 1810 and that by Father Fray Ramón Abella in 1811. Both these missionaries explored the delta region and the rivers but on their way to the valley they passed through the East Bay and left descriptions of considerable interest. A translation of this portion of the diaries is presented without comment and a discussion of the native tribes mentioned is deferred until a subsequent section. _Fr. José Viader's Diary (1810)_ _August 15._ [Left San José Mission and went 6 leagues north to the valley of San José.] _August 16._ In this day, following the same direction, north, we traveled about 6 leagues before noon, and having killed two bears and a very large deer, we stopped to rest at the headwaters of a stream called Walnut Creek. This stream, although it has good water, is running very little. In the afternoon, in the same direction, having traveled another six leagues, having killed a deer and an antelope, and having observed fine country well covered with trees, all without water, we arrived at dark at the end of Walnut Creek. This is at the beginning of some inlets on the northeast side of a well known plain, well covered with trees (among others large walnuts). _August 17._ We passed this day (without moving camp) in scouting the plain and adjacent hills, the lands of which belong to the Tarquines, most, or almost all, of whom are Christians of San Francisco. We have seen the mouth of the two rivers, one of which comes from the north and the other from the southeast. Uniting, they enter one of the estuaries which reach from San Francisco. In all this region, very well known for its climate, fine lands, much wood and walnut groves, the only water we found was one pool of stagnant water, another with good water although its water could not escape, and a spring which flows a little and which is next to the willow grove close to the inlet where it is said used to be the rancheria of the Tarquines. Granting what has been said and that Walnut Creek contains very little water, the area seems to me unsuitable for a foundation. In all this day we killed three bears and 11 deer....