At the end of the 1700s, a French-Canadian trapper travels to the Rockies where he forms friendships and has death-defying adventures while trading with various Indian tribes.
In the early 1800s, French-Canadian trapper Pasquinel lives in the Rockies with Clay Basket and has children with her; he later travels to St. Louis to visit his wife Lise who is raising their daughter.
In the mid 1800s, Levi Zendt, a Mennonite, leaves Pennsylvania with his new wife Elly; the two head west for Oregon and along the way cross paths with Alexander McKeag.
Levi Zendt partners with Alexander McKeag and opens a trading post; later he assists in a historical treaty between the U.S. and the Indian Nations that soon falls apart.
As wars rage across America in the mid 1800s, a militia man from Minnesota, Frank Skimmerhorn, takes his personal vendetta to Colorado in an effort to kill all Indians, including the Pasquinel brothers.
John Skimmerhorn hires R.J. Poteet to lead the difficult cattle drive from Texas to Colorado on behalf of Oliver Seccombe and the Venneford Ranch. Sixteen-year-old Jim Lloyd joins the drive along with cowboys Nate Person, a former slave, Amos Calendar, and Bufe Coker. Meanwhile, Hans Brumbaugh vows to never sell his land to Seccombe.
The town is now called Centennial. The last of the Arapaho led by Lone Eagle leave for a reservation. Hans Brumbaugh refuses to be intimidated by the Venneford Ranch; a range war threatens to erupt when Messmore Garrett brings sheep to the area. Brumbaugh imports a Japanese family to help on his farm.
The circus comes to town and briefly reunites members of the Skimmerhorn cattle drive; Levi Zendt returns to Lancaster, PA for a visit; an accountant uncovers discrepancies in Venneford Ranch's books; a family of actors arrives under the watchful eye of Sheriff Dumire; and Centennial faces a harsh winter.
Oliver Seccombe resigns, but decides to never leave Colorado. The Wendells are determined to stay in Centennial, but can't shake the suspicions of Sheriff Dumire. The killing of the Pettis brothers is not forgotten and Charlotte Seccombe takes over Venneford Ranch. In addition a murder is hidden.
Philip Wendell is tormented as Sheriff Dumire continues his investigation. The Pettis gang is out for revenge. Clemma Zendt returns just as Jim Lloyd and Charlotte Seccombe become engaged. Mervin Wendell jumps at a business opportunity and the first Mexican workers come to Centennial.
In the early 20th century, the Wendells prosper and new families move to Centennial to farm in the dry lands. The Mexican immigrants face discrimination and exploitation. Several prominent citizens pass away while farms struggle during the Depression. Philip Wendell plans to run for Congress and the Grebe family falls victim to the Dust Bowl.
A magazine prepares to do a feature on the history of Centennial; the murder of Soren Sorenson is finally proved; Morgan Wendell and Paul Garrett face off in an election that may determine the future of Colorado's natural resources.
