Before the coming of modern means of transportation, the Missouri River formed the most important avenue of entry into what is now North Dakota. The ascent of the river by the steamboat Yellowstone to Fort Union in 1832 was an event of importance, because the Big Muddy had never before been navigated through this territory.

The Indians who witnessed the coming of this first boat found great significance in it also. According to George Catlin, the artist, who was aboard the steamer, some of them shot their dogs and horses in a sacrifice to appease the Great Spirit, whom they thought to be offended; some ran frightened to their homes; and some among the Mandans cautiously approached the ship, "the big medicine canoe with eyes", which in some mysterious way could see its own way to take the deep water in the middle of the channel.

The frequently changing channel and swift current of the river proved a severe test for the hardy and resourceful pilots who followed in the wake of the Yellowstone. As the Sioux City (Iowa) Register stated in 1868, "Of all the variable things in creation the most uncertain are the action of a jury, the state of a woman's mind, and the condition of the Missouri River."

The humorist George Fitch, as quoted in Edna LaMoore Waldo's Dakota, describes the stream in these words:

"There is only one river with a personality, a sense of humor, and a woman's caprice; a river that goes traveling sidewise, that interferes in politics, rearranges geography and dabbles in real estate; a river that plays hide-and-seek with you today, and tomorrow follows you around like a pet dog with a dynamite cracker tied to his tail. That river is the Missouri."

A pilot familiar with the river, and able to foresee its vagaries, often received—and was easily worth—$1,000 a month, fabulous as that salary may now seem.

The Red River was also a highway of traffic in the heyday of the steamboat. Supplies were carried down it to Grand Forks, Pembina, and Winnipeg (then Fort Garry). The steamboat could be employed only during the summer months, however, when the river was open. During the winters in the 1870's, messages, supplies, and mail were carried by pack horse and dog sled. Regular mail routes were established between Fort Abercrombie and Fort Totten, and from St. Paul to Winnipeg, by way of Pembina.

As news of the vast untouched, wealth of the new Territory drifted back to eastern capitalists, they turned their eyes westward. Soon survey parties mapped the projected courses of railroads. By 1871 the Northern Pacific Railway had been completed as far as Moorhead, Minn. The next year it crossed the river, and in 1873 reached Bismarck, halting at the Missouri. It was no easy task to span this treacherous river; and, with the interruption of the panic of 1873, not until 1879 was there any further westward extension. Construction work to the Montana border was finished in 1881, two years before the Northern Pacific became a transcontinental line. So great was the influence of the railroad in bringing new settlers to Dakota that in the period from 1870 to 1875 the population of the western half of the Red River Valley doubled.

General Custer's expedition returned from the Black Hills in 1874 with glowing tales of gold. There was a rush for the Hills, and Bismarck, the nearest railroad terminus, became temporary headquarters for parties leaving by stage for the gold fields. The route that Custer had taken to the Hills from Bismarck was long known as the Territorial Highway.