April 10 Left Berkeley at 1:00 P.M. with Marianne Hobbs for salt marsh area near Pinole (0.7 mi N, 0.2 mi W.), Contra Costa Co. The Salicornia here had new growth. Some Microtus workings were seen on raised ground adjacent to drainage ditches. This raised ground was covered by grass and perennial shrubs as well as a little Salicornia. Traps (2,5) were set along this raised ground. 25 traps were set along railroad embankment that had a heavy grass cover. Both these lines were parallel and near the eastern (inland) side of the marsh. 45 traps were set along slightly raised ground covered by only Salicornia and in the adjacent part of the marsh. No Microtus signs were seen in the marsh proper. April 11 Returned to Pinole marsh at 8:30 P.M. Trapping results were: Microtus 2; Reithrodonomys ; and Mus. All Microtus were taken along raised ground mentioned above (Apr.10) All but one Reithrodontomys were taken in the same series of traps as the Microtus. April 12 Trapping results at Pinole were: Microtus 3; Reithrodonomys ; Mus . Traps checked at 7:30 A.M. Microtus and Reithos were again taken along raised ground. April 13 Trapping results at Pinole were: Microtus 2; Reitho 2 ; Mus!8 . Microtus from the same place but 2 Reithos were taken in the Salicornia. The traps were removed from the railroad embankment and placed along the raised ground along the drainage ditch W. of the previously placed traps which were not moved. The remaining 45 traps were placed along the top of the high ground between the marsh and the beach. This area is covered by grass and woody shrubs of max height of 10". Signs of Microtus seen in this area. April 14 Traps checked at about 2:00 A.M.: Microtus 0; Reithros 3 ; Mus not sawed but about 15 caught. Accompanied by Marianne Hobbs. Both microtus were taken along raised lander marsh places. Reithos in both Rain of previous night flooded usually dry area. April 15 Traps checked at 7:30 A.M. Microtus 2 ; Reithros 1 ; Mus not catch but about 10 taken. No Microtus from high area beach. We are low again.