The department has the sole authority to issue permits for the establishment, maintenance, and operation of junkyards within the limits prescribed by this part 5. No permit shall be issued unless such junkyard can be effectively screened, as required by regulation, by natural objects, plantings, fences, or other appropriate means so as not to be visible from the main-traveled way of such highways. Such screening shall be at the expense of the person applying for said permit.
C.R.S. § 43-1-504