Shortly after the Verendrye visit the Mandan seem to have declined. When Lewis and Clark came up the Missouri in 1804, the villages about the Heart River were in ruins. Farther up the river, near where it is joined by the Knife, the explorers found the Mandan, diminished by smallpox and by wars with the Assiniboin and the Dakota to two small villages. In 1837 smallpox again broke out, reducing the tribe from 1,600 to 150--some travelers give even a lower figure. At the beginning of the twentieth century it numbered about 250. The other agricultural tribes seem to have suffered fates almost as harsh. The Hidatsa, numbering 2,100 at the time of the Lewis and Clark visit, had been reduced at the beginning of the present century to less than 500. In 1804 the Arikara, crowded by the Sioux, had moved up the river nearer to the other agricultural tribes. Lewis and Clark found them in three villages between the Grand and Cannonball Rivers in what is now North and South Dakota. At that time they numbered 2,600, but this figure had dropped to 380 by the beginning of the twentieth century. The Cheyenne village on the Missouri, some distance below the site of Bismarck, was in ruins at the time of the expedition. Successive migrations finally brought the Cheyenne to the headwaters of the Cheyenne River in the southwestern part of present South Dakota. The agricultural tribes on the whole have been very friendly to the whites. In 1870 a large reservation, which has since been much reduced in size, was set apart at the junction of the Missouri and the Little Missouri Rivers for the Mandan, Arikara, and Hidatsa (_see Side Tour 3A_). Since the beginning of the century their numbers have increased by large percentages and at the present time they number approximately 1,650. The remnant of those Cheyenne who lived in North Dakota are now on reservations in south central Montana and in Oklahoma.