S.C. Code § 57-5-870
The Department of Transportation and the Department of Natural Resources are authorized to enter into cooperative agreements for the construction of access roads and recreation facilities in any county in the State.
The agreements may provide for the Department of Transportation to prepare the necessary plans; provide construction engineering and inspection; and award the necessary construction contracts, subject to the written approval of the Department of Natural Resources. All such contracts shall provide for payments for work performed to be made by the Department of Natural Resources from its funds. Upon completion of the construction work, the Department of Transportation shall reimburse the Department of Natural Resources out of farm-to-market construction funds apportioned to the county in which the work is performed not exceeding the actual cost of constructing any such secondary roads or one half the total cost of the project provided for in the cooperative agreement, whichever is less. The Department of Transportation shall pay from its farm-to-market construction funds apportioned to such county the cost of engineering and inspection. The roads shall become a part of the state highway secondary system upon their completion.
S.C. Code § 57-5-870