Here is a large group of aligned propped boulders, situated on a high hill in northern RI. The propped boulders are yellow and joined by a yellow dashed line.
Starting at the left (west) of the diagram, the first line has two segments. The longer segment is 491 feet long and has a bearing of 293 degrees. The shorter segment is 198 feet and 328 degrees. To the right (east), the second line is 310 feet long and about 32 degrees. They meet at waypoint 1866 at a nearly 90 degree angle. The turquoise waypoint is a massive perched boulder.
Here are the boulders at the waypoints, starting from left to right. These photographs and waypoints were made in November 2011. At the time, I had no idea there was any linear alignment, and was recording every propped boulder at the site.
Waypoint 1873, a group of boulders on an outcrop. The large boulder to the back is propped.
Waypoint 1874, another propped boulder.
Waypoint 1870, a large propped boulder. Planes on the underside of this boulder show where stone has been chipped away.
Waypoint 1868, a propped boulder resting against an outcrop.
Waypoint 1866. This is the intersection of the two lines. The propped boulder rests on two slabs, with an open space in the middle. Perhaps there is some symbolism in this configuration.
Waypoint 1930, a large propped boulder with daylight visible underneath.
Waypoint 1880. The end of the second line.
Waypoint 1869 in turquoise is a prominent perched rock, well known in this area. The long axis faces 105 degrees, and would point to the corner boulder at waypoint 1866.