(a) The portion of Farm to Market Road 70 in Nueces County between its intersection with State Highway 44 and its intersection with Farm to Market Road 1833 is designated as the Los Robles Trail. The designation is in addition to any other designation.
(b) Subject to Section 225.021(c), the department shall:
(1) design and construct four markers indicating the designation as the Los Robles Trail and any other appropriate information; and
(2) erect a marker at each end of the highway and at appropriate intermediate sites along the highway.