Back before there was a United States and even before the was a Delaware, the Duke of York acquired title to all the land within 12 miles of New Amstel by defeating the Dutch. New Anstel then became New Castle and the Duke later gave the land to his friend William Penn to be part of a new colony named after its owner.. The original boundary line for New Castle defined in a 1701 survey was an arc of 12 miles radius with the center in the city of New Castle. The three southern counties of Pennsylvania (New Castle, Kent, and Sussex) would become semi-independent and later form Delaware.
In 1892 the line was resurveyed and truncated pyramidal stone markers were installed at every half-mile along the arc that was now the boundary between Delaware and Pennsylvania. Your first quest should be to find the 2 ½ mile marker—a 3-foot tall 8” square stone should be easier to find than a hidden cache.
The best access to the marker/cache is to use the Wendel Cassel Trail that is show on any of the park maps. The recommended access to the trail is from Pennsylvania on Yeatman’s Station Road. . When Quartz Mill Road goes off to the left, stay to the right (“No Outlet”) and follow Yeatman’s Station Road to the point where there is small area to park as a gated farm road goes off to the right up a hill. The trail is just about 100 feet further down the road on the left side. If you miss this, Yeatman’s Staton Road shortly ends with a small parking area on the right-- walk back up the road approximately ¼ mile to the trailhead.. Follow the trail as it climbs to the head of the valley. When it bears right, go straight and pick up a marked informal trail that goes to the marker. Use the waypoint to find this location.
Or you can access the trail from Delaware. The trailhead is on Corner Ketch Road and is not well marked. It can be found by going approximately 0.2 miles down a very long driveway at mailbox number 1144 and watching for the trail on your left. (This road/driveway is park property so its ok ) The problem with this route is parking which is only available about 0.2 miles further down Corner Ketch Road where it bends sharply to the right (small area of park property where you can park) Use the trail for a short while then look for informal trail to the right.