The first whites to explore what is now Colorado found most of it occupied by branches of two large Indian linguistic groups—the Shoshonean, who claimed the mountain country and a portion of the southern plains, and the Algonkian tribes who held the northeastern plains section. How many they numbered, all told, is uncertain. Existing records are vague and contradictory through want of understanding of Indian tribal divisions, fluctuations in population caused by unremitting warfare, and the predilection of the military to exaggerate the numbers of the foe. The Indians in the State never totaled more than 10,000 persons, according to some historians, but other estimates run twice as high.

The chief tribes on the plains were the Cheyenne, Arapaho, Commanche, and Kiowa. Before the advent of the white men these tribes were bitter enemies, almost constantly at war, with the Cheyenne and Arapaho allied against the Comanche and Kiowa. Less permanent residents of the plains were the Pawnee of Caddoan stock, the Sioux, the Kiowa-Apache, and the Plains Apache, or Lipan. Crow and Blackfoot war parties occasionally penetrated from the north as far as the South Platte River, and in the sixteenth century the Spanish found Navaho along the banks of the Rio San Juan in southwestern Colorado. The Mountain Apache, or Jicarilla, frequently came into Colorado from New Mexico and Arizona to make raids on the plains tribes and to trade with their friends, the Ute.

The mountain-dwelling Ute, Colorado's chief representatives of Shoshonean stock, appear to have been the only indigenous tribe of Colorado; all others were migrants who came in a series of waves set in motion by the pressure of stronger peoples behind them. The seven tribes of Ute in the State were grouped in four major divisions—the Southern Ute, which included the Capote, Moache, and Wiminuche bands; the White River Ute, made up of the Yampa and Grand River tribes; the Tabeguache Ute, comprising the Tabeguache proper and the Uncompahgre; and the Uintah Ute, embracing a number of tribes largely resident in Utah although a few lived in the extreme northwestern corner of Colorado. The Ute tribes were in turn subdivided into smaller bands, each with its own name and civil organization. Great differences in dialect and culture characterized these divisions, as was to be expected in a tribe so widely scattered and inhabiting territory as diverse as the mountain fastnesses in the central part of the State and the semiarid plateaus to the west and south. The Ute held the entire mountain region, guarding the low passes against the plains Indians with whom they were constantly at war. This unremitting warfare proved a source of irritation and alarm to white communities near the foothills, for war parties on raid and counterraid constantly threatened the new settlements. On one occasion a party of Arapaho, after an unsuccessful attack upon the Ute, sought refuge in the very heart of Denver, to the anger and dismay of the inhabitants, who knew that the pursuing Ute would not distinguish between their hereditary enemies and the whites who ostensibly were offering them shelter. Fortunately, the mountain warriors turned back before they reached Denver.

The Ute were never really conquered; in the end, they were turned to the ways of peace by their chiefs—notably, the great Ouray, always a friend of the whites. As early as 1705 the Ute joined a conspiracy of the Navaho and other tribes against the Spanish; later, they frequently raided the Spanish settlements in New Mexico for horses, scalps, and plunder. Governor Cossio of New Mexico led a punitive expedition against them in 1719, but the mountain warriors eluded him and the raids upon the Spanish settlements continued. On Christmas Day 1854, a band of Ute under Tierra Blanca captured old Fort Pueblo (see Pueblo) and massacred all but a Mexican woman and two children. The woman was later killed, but the children were finally returned to their people. In 1855 the Tabeguache band under Kanakache attacked the Spanish colony at Guadalupe but were decisively defeated (see Tour 15c). A second expedition from New Mexico took the trail of the hostiles, and defeated them in several engagements with heavy losses. The Ute finally sued for peace, returning hostages and much plunder. Subsequently, the attitude of the Ute toward the white settlers who were gradually encroaching upon their hunting grounds was far from friendly, but was rarely openly hostile. Ranchers were occasionally killed, and from time to time prospecting parties were wiped out, but no serious outbreak occurred until 1879 when the increasing resentment of the Ute culminated in the Meeker Massacre (see Tour 17).

Earlier, by a treaty in 1868, the Federal Government had assigned the Ute a large part of southwestern Colorado, but with the discovery of rich mineral deposits in this region steps were taken to recover it. In 1873, largely through the counsel of Ouray, the Ute ceded the mineralized San Juan district. As late as 1874, however, they retained title to 15,500,000 acres on the Western Slope and occupied most of the territory west of the Continental Divide. In 1881 the Northern Ute who had participated in the Meeker Massacre were removed to a reservation at Uintah, Utah. One last abortive attempt to reclaim their old lands was made by a band under Colorow; after this failure the Ute made no further resistance. The Southern Ute were subsequently placed on a small reservation in the barren southwestern corner of the State (see Tours 11D and 11E). Intermarriage between the Ute and the Jicarilla Apache was common. The celebrated Ouray or more correctly, Ure—was born of such a union, his mother being a Jicarilla; Chief Colorow was likewise of mixed Ute and Apache blood.

The Comanche, first of the plains tribes to appear in Colorado, were driven from their home in the Black Hills by the Sioux; they moved southward, pushed by the war-like Kiowa, whose allies they later became. As the Comanche were of Shoshonean stock, they were friendly for a time with their kinsmen, the Ute; later estranged for some unknown cause, the two tribes became bitter enemies. After their arrival in Colorado, where they ranged the extreme southern part of the State, they became a nation of fierce and ruthless fighters, the scourge of the settlements in New Mexico and Texas; they extended their depredations deep into old Mexico, where they were hated and feared above all other tribes. The Comanche were accomplished horse thieves and raiders, and grew tremendously rich in horses, general plunder and hostages; they carried off white women and children and held them for ransom, which was usually paid in the form of ammunition, whisky, and supplies. Women captives were frequently taken as legal wives by chiefs and warriors, and some of these women refused to leave their husbands when their ransom was paid. Quanah Parker, the great Comanche chief, was born of such a union; his mother, Cynthia Parker, had been stolen by Comanche raiders when a child and refused to return to her people.

Next to arrive in Colorado were the Kiowa, or Ka-i-gwa, "principal people." Of unknown origin, they are classed as a separate linguistic unit, for little similarity exists between their tongue and that of any other tribe. Although few in number, they were regarded as the most predatory and bloodthirsty of all the plains Indians, and are said to have killed more whites in proportion to their number than any other tribe. They took possession of a region south of the Arkansas River, and after fighting the Comanche for years, made an alliance with them, sharing a large territory as hunting grounds, harrying white settlements in every direction. The Kiowa played an important part in the Indian wars between 1861 and 1869, and also in the "Buffalo War" of 1873-74, when the allied Cheyenne, Arapaho, Comanche, and Kiowa made a last desperate stand against white hunters who were destroying the few remaining large buffalo herds in Oklahoma and Texas.

On the heels of the Kiowa came the allied Cheyenne and Arapaho. The war-like Cheyenne took the lead in almost all policies of war and peace, and the Arapaho usually followed their tempestuous allies. The Cheyenne called themselves Tsis-tsis-tas, variously translated as "similarly bred," or "the slashed people"; the tribal sign signified "cut" or "slashed." The name by which they are commonly known is a corruption of the Siouan word Sha-hei-la, "people of alien speech." Originally an agricultural people, the Cheyenne had long since become buffalo hunters as they were relentlessly forced west and south by the Sioux. At some unidentified period during this slow migration they formed their lasting friendship with the Arapaho. Entering Colorado, they drove the Kiowa southward to crowd the belligerent Comanche and precipitate a flurry of intertribal wars. From these conflicts the Cheyenne and Arapaho finally emerged triumphant in undisputed possession of the territory north of the Arkansas and east of the mountains.

After the construction of Bent's Fort on the Arkansas River in 1832 (see Tour 9A), the Cheyenne tribes divided. One part migrated to the Arkansas Valley and became known as Sowonia, or "Southerners," while the other part remained about the headwaters of the North Platte and the Yellowstone Rivers. This split, designed to facilitate trading with the trappers who came to Bent's Fort, weakened them and hastened the destruction of their tribal organization.

The plains Indians were not easily subdued. In 1840 a great council had been held on the banks of the Arkansas River, at which Cheyenne, Arapaho, Kiowa, and Comanche settled their differences and formed an offensive and defensive alliance against other tribes and the increasing menace of white immigration. This treaty was never broken, and the alliance of the Four Nations had far-reaching effects upon the history of the West. Presenting a united front against invaders of their buffalo lands, these fierce and implacable tribes made a determined stand in defense of their homes.

From their first contact with the whites, the Arapaho and Cheyenne were alternately hostile and friendly, often changing for no apparent reason. The earliest pioneers found them almost universally opposed to white invasion, although they were friendly enough toward Bent and other traders. They were continuously hostile between 1855 and 1857, when the military took the field against them and defeated them with considerable losses. In 1861 the two tribes concluded a treaty with the Federal Government by which they relinquished all claim to the greater part of their Colorado lands. A temporary peace followed, but failure to fulfill promises made to them in regard to annuities and other matters brought renewed raiding; this in turn led to the Sand Creek Massacre (see Tour 8a), in which the Southern Cheyenne received a stunning blow. Ten years of almost continuous warfare followed this ill-advised affair. Northeastern Colorado, Nebraska, and Kansas were ravaged, with inestimable losses in life and property. Julesburg and most of the stage stations in the South Platte Valley were destroyed; wagon trains were burned, and all trails were virtually closed.

Gradually the tide of warfare turned against the Indians. In 1868, at Beecher Island on the Arickaree River (see Tour 3), the Cheyenne lost one of their greatest leaders, Roman Nose, and their failure here to defeat a foe numerically so much weaker did much to shake their morale. That winter, in Nebraska, Chief Black Kettle's village on the Washita River was destroyed, and in the summer of 1869 Tall Bull was defeated at Summit Springs (see Tour 1a). The hostiles were continuously harried until the last of the Southern Cheyenne surrendered in 1874 and were settled on a reservation in western Oklahoma. The Northern Cheyenne, still irreconcilable, joined Sitting Bull in the Sioux War of 1876, participating in the Custer Massacre and in Brook's Battle on the Rosebud. In the winter of 1878-79 the larger bands of hostile Cheyenne under Chiefs Dull Knife, Wild Hog, and Little Wolf surrendered and were removed to Fort Reno, Oklahoma, to be settled with the southern unit of the tribe. After considerable friction generated by their not unnatural dislike of a strange land so different from their home, they were assigned to the present reservation in Montana. Little Wolf and his people, after their final capitulation, became scouts for the Army and saw active service against the still hostile Sioux.

The Arapaho roamed a narrow strip of plains country along the front range of the Rockies, between the Cache la Poudre and Arkansas Rivers. Like the Cheyenne, they divided into a northern and a southern branch ; the former held the country north of the South Platte River, while the latter occupied the valley of the Arkansas, along with the Southern Cheyenne, with whom they fought side by side during the wars of the 1850's and 1860's, and with whom they shared land in the Oklahoma reservation. The Arapaho, although a milder people than their allies, were savage fighters when aroused and bore an enviable record for prowess. There was a strong infusion of Arapaho blood among the Cheyenne, but the tribal stock of the former remained almost pure; Cheyenne men frequently married Arapaho women, but, curiously, there is no recorded instance of a marriage between an Arapaho brave and a Cheyenne girl. Arapaho, although sometimes translated as "tattooed people," is a corruption of the Pawnee word Lirapahu, "traders." Their own name for themselves was Inuniana, "our people."

The last tribe to enter Colorado and claim hunting grounds were the Pawnee. They came from far to the south, and die record of their journey to the West is unknown. They first made their headquarters on the Republican River some three hundred miles east of the Rockies, and in Colorado their territory embraced only the extreme northeastern corner of the State. Bitter enemies of almost every other tribe, they were notable fighters individually, but as a group they were relatively weak and on the eve of white settlement they held their semiarid hunting grounds largely on the sufferance of stronger neighbors who sought more desirable territory. Of all Colorado tribes the Pawnee alone were consistently friendly to the whites, seldom resorting to war, waiting patiently for the Federal Government to right any wrongs they had suffered; many Pawnee served with the Army against the "hostiles." A semisedentary people, the Pawnee crudely cultivated small gardens and lived during the summer months in makeshift dwellings of logs, sod, and bark. The remainder of the year they roamed the plains on hunting expeditions, living in skin lodges, supplementing their limited vegetable diet with meat. When the Indian wars were over, the Pawnee, too, were settled on reservations in Oklahoma and Texas.