After the treaty commission failed to persuade the Lakota to give up the Black Hills, the President had an ultimatum sent in January 1876 to the northern bands to come into the agencies or be forced in by the army.

He Dog's brother, Short Bull, later recalled that the majority of the northern Oglala resolved to head in to the Red Cloud Agency in the spring, after their last big buffalo hunt.

In March 1876, He Dog married a young woman named Rock (Inyan) and with part of the Soreback Band, stopped briefly with the Northern Cheyenne encamped on the Powder River in Wyoming Territory.

He Dog and other members of the Soreback Band fled the Red Cloud Agency after its removal to the Missouri River during the winter of 1877–78.

He served as a respected Indian judge and later in life, was interviewed by a number of historians, including Walter Mason Camp, Eleanor Hinman and Mari Sandoz.