The land surrounding Lake Whitney is known as one of the best places in the state for fossil hunting. Visitors to any of the local parks can walk the shoreline in search of fossils, rocks, petrified wood, and other interesting finds.
While it can be fascinating just to see what you can find, keep in mind that the shoreline of Lake Whitney is owned by the Corps of Engineers, and they do not permit removal of any items.
If you want to venture out further to see pre-historic artifacts, there are two nearby locations. Dinosaur Valley State Park in Glen Rose has numerous tracks embedded in the riverbed there. The newly opened Waco Mammoth Site, along the Bosque River in Waco, houses a dig shelter and remains of some of the more than 20 mammoths and other pre-historic animals found at that location.