The State trails system shall be composed of the following classes of trails:
a. State scenic trails, which will be extended trails so located as to provide maximum potential for the appreciation of natural areas and for the conservation and enjoyment of the significant scenic, historic, natural, ecological, geological, or cultural qualities of the areas through which such trails may pass. Each of these trails will be limited exclusively to foot use, except that the use by horses or nonmotorized bicycles may also be permitted on segments of scenic trails where deemed appropriate by the department.
b. State recreation trails, which will provide a variety of outdoor recreation uses in or reasonably accessible to urban areas.
c. Connecting or side trails, which will provide additional points of public access to State scenic or recreation trails or which will provide connections between such trails. They shall be of the nature of the trails they serve.