The branches are in Price, Fairview, Mt. Pleasant, Nephi, Loa, St. George, and two in Ephraim.
The acquisition is expected to close sometime between July and September, Cache Valley CEO Gregg Miller said Tuesday.
The branches will continue as AmericanWest banks until the sale closes and then become Cache Valley banks, Miller said.
Cache Valley has seven branch offices in Logan, Layton and St. George. The bank will have 15 locations in seven Utah counties after the sale.
The new branches "are a fit with our ability to operate in communities in Utah and provide excellent markets for the bank to grow its base in the future," Miller said.
Cache Valley already has branches in St. George. The bank bought SunFirst Bank in November 2011. It purchased three offices from Village Bank last year.
American West spokeswoman Kelly McPhee said the Spokane, Wash.-based bank isn't pulling out of Utah. Instead, it is selling branch offices that no longer fit with the community bank's growing focus on commercial lending.
Nine other AmericanWest offices, all between Salt Lake City and Provo, aren't part of the sale. AmericanWest plans to open a 10th office in Bountiful in mid-July, McPhee said.
AmericanWest CEO Scott Kisting said community banking has changed a lot since it acquired the banks almost a decade ago.
"Today's banking environment requires a greater level of strategic discipline to not only compete but to be an exceptional company," Kisting said in a statement.
"This sale was a difficult decision, yet we know it was the right thing to do because it more closely aligns our [territory] with our [increased] business banking focus," he said.