15 U.S.C. § 265 : US Code - Section 265: Transfer of certain territory to standard central-time zone

Search 15 U.S.C. § 265 : US Code - Section 265: Transfer of certain territory to standard central-time zone

The Panhandle and Plains sections of Texas and Oklahoma are
transferred to and placed within the United States standard central-
time zone.
The Secretary of Transportation is authorized and directed to
issue an order placing the western boundary line of the United
States standard central-time zone insofar as the same affect Texas
and Oklahoma as follows:
Beginning at a point where such western boundary time zone line
crosses the State boundary line between Kansas and Oklahoma; thence
westerly along said State boundary line to the northwest corner of
the State of Oklahoma; thence in a southerly direction along the
west State boundary line of Oklahoma and the west State boundary
line of Texas to the southeastern corner of the State of New
Mexico; thence in a westerly direction along the State boundary
line between the States of Texas and New Mexico to the Rio Grande
River; thence down the Rio Grande River as the boundary line
between the United States and Mexico: Provided, That the Chicago,
Rock Island and Gulf Railway Company and the Chicago, Rock Island
and Pacific Railway Company may use Tucumcari, New Mexico, as the
point at which they change from central to mountain time and vice
versa; the Colorado Southern and Fort Worth and Denver City Railway
Companies may use Sixela, New Mexico, as such changing point; the
Atchison, Topeka and Santa Fe Railway Company and other branches of
the Santa Fe system may use Clovis, New Mexico, as such changing
point, and those railways running into or through El Paso may use
El Paso as such point: Provided further, That this section shall
not, except as herein provided, interfere with the adjustment of
time zones as established by the Secretary of Transportation.