Initial Rock, archaeological site in North Dakota

Initial Rock is a sandstone boulder in the Little Missouri National Grassland near Medora, North Dakota, bearing the carved names of two soldiers, W.C. Williams and F. Neely. A shelter erected over the rock in 1966 protects the inscriptions from weathering and vandalism. The surrounding 9.9-acre site was listed on the National Register of Historic Places in 1976.

Initial Rock was the site of an overnight camp on May 28, 1876, when men of George Armstrong Custer's command passed through on their way to the Battle of the Little Bighorn, fought on June 25, 1876. Two soldiers of Marcus Reno's command, W.C. Williams and F. Neely, carved their names in the rock, which is still at the site; both survived the battle. The site was listed on the National Register of Historic Places in 1976.

Initial Rock lies in the Medora Ranger District of the Little Missouri National Grassland, reached by a gravel road off the Custer Military Trail driving tour. A shelter erected over the boulder in 1966 protects the carvings, so the inscriptions stay legible in any season. The surrounding grassland is open rangeland; carry water and fuel, as services are in Medora.

Both soldiers who carved their names survived the Battle of Little Bighorn, which sets them apart from most others in that campaign. This fact makes the inscriptions a rare connection between survivors and the moment they passed through this remote landscape.