The Texas company would add seven branches and more than $300 million of assets by acquiring Valley Bancorp.
The company will add two branches between Denver and Colorado Springs by buying the deposit-rich Castle Rock Bank.
The company will also gain its first branches in New Mexico after it buys Peoples Inc.
The city is booming thanks to its rising population, revitalized downtown and diverse economy, attracting bank buyers and de novo interest.
The Montana company has agreed to buy Columbine Capital in a deal that will add five branches and $330 million in loans in Colorado.
Koger Propst was also named CEO of the company's $2.6 billion-asset ANB Bank.
The Denver bank had spent the last two-plus years addressing concerns about capital and underwriting procedures.
