The most important rules are listed here, and the whole Trails Use Policy document, INCLUDING ALL CURRENT TRAIL DESIGNATIONS is posted.
1. All trails are open to pedestrians and closed to other uses. All allowable trails will remain as they are until a change order is made by the Superintendent. (The new signs then will be "Bikes allowed" or "Horses Allowed.")
2. The speed limit on trails are 15 MPH, unless approaching another trail user or on a blind hill or curve, then 5 MPH. The Department may establish additional speed limits for designated trails use. When established, these speed limits will be posted.
3. No person should operate a bicycle in such a way as to endanger hikers, equestrians or others using State Park property.
Too see the whole document, click on the link above.