N.M. Stat. § 4-25-1
That the present county of San Miguel is hereby abolished and there is hereby created the county of Jefferson out of the area formerly in San Miguel county and also out of a triangular area within the Pablo Montoya grant, lying between the counties of Guadalupe, Quay and San Miguel as it heretofore existed, which said county of Jefferson shall be described and its boundaries shall be as follows, to wit:
beginning at the southeast corner of the Baca location no. 2; thence west on the south boundary of the Baca location no. 2, to the southwest corner of the same; thence north on the west boundary of said Baca location no. 2, to a point where it intersects the southeast boundary line of the Pablo Montoya grant; thence southwesterly along the southeast boundary line of the Pablo Montoya grant to a point where the same intersects the east boundary line of Guadalupe county; thence north along the eastern boundary line of Guadalupe county to the northeast corner of said county; thence west along the north boundary line of Guadalupe county to the northwest corner of Guadalupe county; thence south along the west boundary line of Guadalupe county to the northeast corner of Torrance county; thence west along the north boundary line of Torrance county to the southeast corner of Santa Fe county; thence north along the east boundary line of Santa Fe county to a point where the same is intersected by the south boundary line of Mora county; thence in an easterly direction following the south boundary lines of Mora and Harding counties to a point where the same intersects [intersect] the northwest boundary line of the Pablo Montoya grant; thence northeasterly along the northwest line of the Pablo Montoya grant to the northeast corner of said grant; thence southeasterly along the easterly boundary line of the Pablo Montoya grant to its points of intersection with the north line of the Baca location no. 2; thence east along the north boundary line of the Baca location no. 2 to the northeast corner of said Baca location no. 2; thence south along the east boundary line of the Baca location no. 2 to the southeast corner of said Baca location no. 2, and place of beginning.
NMS § 4-25-1