Cal. Gov. Code § 23111
The boundaries of Glenn County are as follows:
Beginning at a point on the eastern boundary line of Lake, at the northwest corner of the SW. 1/4 of Sec. 26, T. 18 N., R. 8 W., M. D. B. & M.; running thence east along the half section line, and one and one-half miles north of the line dividing T. 17 and 18 N., M. D. B. &. M., to the range line separating T. 18 N., R. 2 W., from T. 18 N., R. 3 W.; thence running north two miles to the northeast corner of the SE. 1/4 of Sec. 13, T. 18 N., R. 3 W.; running thence east along the half section line to the center of the Sacramento River; thence down the center of the said Sacramento River, in a southeasterly course, to the point of intersection with the half section line, one and one-half miles north of the line dividing T. 17 and 18 N., M. D. B. & M.; thence east on said half section line to its intersection with Butte Creek, said point of intersection lying on the western boundary of Butte and being the southeastern corner of Glenn and the northeastern corner of Colusa; thence northerly along the middle of the channel of said Butte Creek to the point of intersection with the line between Secs. 3 and 4 of the Aguas Frias Rancho as surveyed by La Croze; thence north along the said line between the said Secs. 3 and 4 to its point of intersection with the line between T. 19 N., R. 1 E., and T. 20 N., R. 1 E.; thence west along said line to its intersection with the southern boundary of the Llano Seco grant, on the north line of Sec. 2 in T. 19 N., R. 1 W.; thence southwest along said grant line to the southwest corner of said grant in the center of the Sacramento River; thence northerly, and following the meanderings thereof, along the center of said Sacramento River, to a point where the north line of T. 22 intersects the center of the Sacramento River, being the initial point of Tehama; thence west along the north line of T. 22 N., to the southwest corner of Tehama; thence southerly on the established line between Mendocino and Lake to the place of beginning.
Ca. Gov. Code § 23111