Rock Springs Reserve features 12 miles of hiking trails near Sanford, FL.
Take I-4 to the SR 46 exit at Sanford. Turn left pass the Wekiva River. The entrance to Rock Springs will be on the left just past the bear underpass fencing. The bike trail head is about a quarter mile past the pay station ($2.00 entry fee) on the left.
http://www.tripleblaze.com/trail.php?c=3&i=2140