Spain sent out expeditions from Mexico City in the 1600's and discovered Indian settlements in and around current day Bent County boundaries. The Spanish named the Indians collectively as Apache.

The first recorded French explorers were the 1739 expeditions of the Mallet brothers. French influence on the area grew as several more French expeditions were made using the route that was to become the Santa Fe Trail.

After the French and Indian War of 1754 broke out, France bribed Spain with the Louisiana Territory to become their ally against England and all of Colorado became Spanish territory. Even though in 1792, Pedro (Pierre) Vial, a French explorer under the New Spain government, set out to establish a trade route between St. Louis and Santa Fe, Spain re-ceded the Territory to France in a secret treaty in 1800. France retained ownership until it was sold to the United States.

Robert Livingston and James Monroe had been in France bargaining for the port of New Orleans when Napoleon offered to sell the whole territory for $15 million. Although unauthorized by Congress, they grabbed it. When they asked what the territorial boundaries were, Napoleon's response amounted to "whatever you can hold." The land bordering the Mississippi River west to the Arkansas River became contested territory between the Spanish and the Americans. Spain attempted to protect its' claim when they heard about explorers and trappers making their way through Spanish-claimed land.

In the summer of 1806, Captain Zebulon Pike lead one of the first expeditions to explore the area. Starting in St. Louis, he set out to explore the new territory and mapped his travels along the Arkansas River. He was also acting as a spy on this famous expedition searching for evidence of Spanish colonization and military strength, and to what extent. It was in Bent County, near the confluence of the Purgatoire and the Arkansas Rivers, that he first sighted the peak, now known as Pike's Peak, about 140 miles to the northwest

After Mexico gained its' independence from Spain, Mexico and the United States established friendly relations and Mexico was eager for trade. The Americans were glad to oblige.

It is believed that William Becknell was the first to make the trip in 1821 with trade goods, earning the name "Father of the Santa Fe Trail".

The Santa Fe Trail extended some 780 miles, from Westport (now Kansas City) on the Missouri River to Santa Fe, where it connected with El Camino Real, which led deep into Mexico. Over the Santa Fe Trail moved large caravans of freight wagons. Much of its course was a narrow beaten track where the wagons followed only a general path over the tough plains grass. While the route was not without its dangers, descriptions of it as colored with blood were grossly exaggerated; Indians virtually never attacked a well-organized caravan, and only eight men died on the trail in its first ten years.

Bent's Fort was the creation of a trio of traders, Ceran St. Vrain and Charles and William Bent. St. Vrain, and the Bent brothers, met in the wretched winter of 1828 somewhere on the far side of the Divide. By the end of 1830, the Bents and St. Vrain had a profitable business running between Santa Fe and Missouri. Charles Bent proposed joining forces with St. Vrain, who though reluctant, agreed.

The first Bent's Fort was underway by 1833. First called William's Fort, the adobe "mud castle" was so sturdy William Bent had trouble blowing it all up in 1849.

Business began declining in 1848. William Bent offered to sell the fort to the Army, but it declined, hoping to acquire it without cost. The Army lost its gamble. In August 1849 William Bent evacuated the Fort, rolled kegs of powder into the main rooms and blew it up. A re-creation of Bent's Old Fort can be seen today between Las Animas and La Junta.

William Bent went on trading with the Indians, particularly with the Kiowa, Arapaho, Comanches and Cheyenne. Business was so good that in 1852 he began building a new stone fort, east of the old one. Trappers and traders were replaced by gold seekers and soldiers.

In 1860 Bent leased the new fort to the government for the military units dealing with the Indians. The Army built several temporary barracks around the outside walls of the stone fort and called it Fort Lyon. The site would become Fort Lyon Veterans Administration Hospital in the next century.

The government paid little rent on the fort. When Bent went to Washington to collect, he was told he was a "trespasser" on Indian land, with no title to it. By then he was living at another of his stockades and the Army was building a new Fort Lyon because a raging flood had rendered the old one useless. Remains of both Bent's Forts were later used as stage stations. Bent's old friend Kit Carson died at Fort Lyon in May 1868. William Bent died in May 1869 and was buried, "shaded by a clump of large cottonwood trees," on his Purgatoire ranch. His body was later reburied in Las Animas Cemetery in 1906.

In 1841, a Preemption Act was passed to tempt homesteaders onto the uninhabited land of the new west. The homesteader could live on his choice of 160 acres for six months and buy it for $1.25 an acre. The Preemption act lead to the Homestead Act, which was passed in 1862. This Act required a maximum filing fee of $16 on 160 acres of land, live on the land and make substantial improvements for a minimum of five years.

Until 1848 the southern plains, the Rockies, and the plateau country of Colorado were in Spanish and Mexican hands. The remainder of the Colorado plains and the Front Range belonged to the U.S. On February 28, 1861, Colorado became a territory. Much of the eastern plains remained Kansas Territory, while the southern plains were New Mexico Territory.

Around 1868, the trading era was at its end and a new era known as the "Wild West" was beginning. Ranches, cowboys and cattle replaced the Indians and the buffalo and trains were replacing wagons. With the coming of the railroad several towns sprang up along the route. A new land office was to be established in eastern Colorado (the closest land office was in Pueblo) to process the flood of homestead applications and Grenada was the logical site. However, promoters who were not part of the Grenada boom formed plans with the officials of the Santa Fe Railroad in search for a new site. The results of the search became the City of Lamar, which was established and incorporated in 1886.

The original Colorado Territory authorized 17 counties, and an Indian reserve, as required by law. What would become Bent County was, in 1861, partly in the Indian Reserve and partly in Las Animas County. In 1870 the Reserve was divided into Greenwood and Bent counties, Bent being about half the size of Greenwood. W.H. Greenwood was a Kansas Pacific railroad official. By 1876 Greenwood had been merged into Bent County, running 108 miles from the Kansas border to slightly west of what is now Fowler, and 84 miles north to south. In 1889 the legislature divided Bent County, into six parts, each of about a million acres, and each with county seats within a day's horse-and-buggy travel time for the pioneers. These new counties were: Prowers, Kiowa, Otero, Cheyenne, and Lincoln, as well as a much smaller Bent.

The first county seat in Bent County was Boggsville. Developed in 1867 by ranchers--Robert Bent, Thomas Boggs, John W. Prowers, and Kit Carson. The clutch of ranches had a school, general store and stage stop. John Prowers' home was the county seat for the newly created Bent County. The Bent County Commissioners met in Prowers' living room in 1870, and elected him chairman.

Boggsville was the center of civilization in Southeastern Colorado during the 1860s and early 1870s. It boasted the first irrigation canal used in this valley. Agriculture has thrived ever since because of a vast network of canals.

As the area developed, a speculative new town called Las Animas City sprang up across the Arkansas River from Ft. Lyon in February 1869. Five months later, a bridge across the river was built. With this bridge and new town in existence, travel along the Santa Fe Trail make a major shift to the south side. Las Animas City took away the possibility of Boggsville becoming a town. Boggsville still served as the center of education and culture until 1874 while Las Animas City attained the reputation of being too rough and wild for such refinements.

Then came the railroads! In October 1873, the Kansas Pacific Railroad built a branch line south from Kit Carson heading for Ft. Lyon when suddenly it turned west, crossed the Arkansas River and built its own town - West Las Animas. Another boom town at the end of the railroad! Prior to this event , the AT&SF Railroad had stopped at Granada which increased freight and immigrant travel through Boggsville toward another boom town called Trinidad. By mid-1875 the AT&SF reached West Las Animas and both railroads competed for business at this temporary eatstern terminus of the Santa Fe Trail. In the meantime, Las Animas City began its slow agonizing death. Boggsville, in turn, did not die. It was just caught up in the progress of settlement of the Arkansas and Purgatoire Valley. Boggsville gradually became just another farm and ranch so common in this region be 1880.

In 1909, an enlarged Homestead Act was passed, which allotted 320 acres in the dryland or partly dryland areas. However, by 1916, claims were allowed for 640 acres in stock range country. The time limits were changed from five years to three years.

With the second wave of homesteaders, new towns sprang up, and with them came the era of modern technology and agri-business. The county has grown, but it is still primarily farming and ranching. The Fort Lyon VA Medical Center, located east of Las Animas, is now the Colorado Department of Corrections, Ft. Lyon Correctional Facility and is being used as prison hospital.

The area of the confluence of the Purgatoire River with the Arkansas River was chosen to become the vast John Martin Dam in 1936. In addition to storing water for irrigation, it has become a prime recreation area and a State Park.

The population of Bent County in 1870 was 591. In 1873 it had grown to 3,850. In 1900 the population was 3,049; and in 1940, 9,653.