California Code, Government Code - GOV § 23105

The boundaries of Calaveras County are as follows:

Beginning at the southern corner, at a point in the Stanislaus River where it intersects the eastern line of Stanislaus, being a point one mile north of Knight's Ferry, and being the western corner of Tuolumne; thence up said river and north fork thereof, to the westerly line of Alpine; thence northerly, on the line of Alpine, to the southeast corner of Amador; thence southwesterly, on the southern line of Amador, down the Mokelumne River, to the southwest corner of Amador, on the eastern line of San Joaquin County; thence southerly and southeasterly, on the line of San Joaquin and Stanislaus to the place of beginning.