Des Moines airport breaks ground on $445 million terminal
www.kcci.com
The state-of-the-art terminal will have 18 gates, expanded security areas, enhanced gate operations, the latest baggage handling systems and elevated dining and retail.

They are spending 445 million USD on this.

I wonder how many of these flights are to other Midwest cities that could be easily replaced with HSR?

They could even build the rail station into the airport. It is on the edge of the city so there is ample space.

If I were king of the US, I’d connect all of the Major Midwest cities between the Appalachians and Rockies and then run the lines through the SW desert cities and then north up to Spokane and Seattle. Building through the mountains is expensive, so let’s not make perfect the enemy of good and go after the most cost effective locations. It would be feasible to run lines from Miami up to Bangor too. Connect it to the Western system through the deep south cities.