Some historians have estimated that Red Cloud's warriors numbered up to 4,000 men. The total number of Lakota in 1865 was about 13,860. The Northern Cheyenne and Arapaho numbered about 3,000, adding up to a total of about 17,000 Indian men, women, and children. Thousands of people in all three of those tribes were not in the Powder River country with Red Cloud; others stayed aloof from warfare. As had been typical of United States militias, Indian men were part-time warriors. They had to spend much of summer and fall each year hunting buffalo and other game to feed their families. In the late winter and spring, they were limited in mobility until the grass turned green and their horses could recover their strength after the severe winters of the northern Great Plains. The effectiveness of Indian forces were diminished by their lack of cohesion and organization.