Maps like this that break down the regions are better and make more sense. Some edits I would make based on what I know about these states:
Colorado
Move the Southwest region higher up along the Front Range to just south of Colorado Springs including the cities of Trinidad and Pueblo and the San Luis Valley. That portion of Colorado is culturally different than the "Northern Front Range" which includes Colorado Springs and the Denver/Boulder metro. I would keep that mixed with Mountain Frontier but the drop-off to Upper Midwest is just outside Denver. Some would even say that Denver is the largest Midwestern city outside of the Midwest because of its similar built form and all of the Rust Belt transplants.
Honestly there should be another region within Upper Midwest to distinguish the high plains of Colorado, Nebraska, Wyoming and the Dakotas from the farmland of Iowa, southern Minnesota and the Red River Valley including eastern North and South Dakota. There should be another subregion for Northern Minnesota which is unlike anything else in the U.S. with its forests and lakes, and the Boundary Waters.
Oklahoma
Pretty accurate showing how Oklahoma City and Tulsa have more in common with Kansas City and Omaha but a good portion of the state aligns more with the culture of the South. And then there is the Ozark topography and culture which is completely different than the rest of the state. Tulsa is on the edge of this subregion and as a result is a very different city than OKC even though they are only 90 miles apart.
Texas
Shows how Texas functions as its own subregion, which is a blend of the South and Southwest. I would move the Texas region further west to encompass the Permian Basis oil drilling area around Midland. The only true "non-Texas" Southwest area is around El Paso down to Big Bend National Park. I would also extend the High Plains region I mentioned for Colorado down to include the Texas and Oklahoma panhandles. That subregion would go from Lubbock TX all the way up to South Dakota.
You could make a case for a couple of sub-regions within "Texas": north coastal from Corpus Christi up to Beaumont; piney woods in the eastern part; north texas around DFW; Austin and the Hill Country; San Antonio and points south; and the borderlands in the Rio Grande Valley (only predominantly Spanish-speaking area within the continental U.S.)