The boundaries of Marin County are as follows:
Beginning in the Pacific Ocean at the southwestern corner of Sonoma; thence southeasterly along the southern line of Sonoma, to the mouth of Petaluma Creek; thence to the common corner of Marin, Sonoma, Contra Costa, and Solano, in San Pablo Bay; thence southerly along the western boundary of Contra Costa, in the Bay of San Pablo, to the middle of the Straits of San Pablo; thence southerly, in a direct line, to Invincible Rock, in the Bay of San Francisco, near the entrance of the Straits of San Pablo; thence, in a direct line, to the northwestern point of Red Rock; thence southerly to the extreme southerly point of Angel Island; thence southwesterly to the extreme end of Point Cavallo at low-water mark; thence on the line of low-water mark along the northern shore of the bay to Point Bonita, and three miles into the Pacific Ocean, to the northwestern corner of San Francisco; thence northwesterly by ocean shore to the place of beginning.
23100
23101
23102
23103
23104
23105
23106
23107
23108
23109
23110
23111
23112
23113
23114
23115
23116
23117
23118
23119
23120
23121
23122
23123
23124
23125
23126
23127
23128
23129
23130
23131
23132
23133
23134
23135
23136
23137
23138
23139
23140
23141
23142
23143
23144
23145
23146
23147
23148
23149
23150
23151
23152
23153
23154
23155
23156
23157
23158
23101
23102
23103
23104
23105
23106
23107
23108
23109
23110
23111
23112
23113
23114
23115
23116
23117
23118
23119
23120
23121
23122
23123
23124
23125
23126
23127
23128
23129
23130
23131
23132
23133
23134
23135
23136
23137
23138
23139
23140
23141
23142
23143
23144
23145
23146
23147
23148
23149
23150
23151
23152
23153
23154
23155
23156
23157
23158