The Office of the Comptroller of the Currency (OCC) said today that federally chartered banks and thrifts in Iowa, Nebraska and South Dakota have recovered from the financial crisis. In the three-state area, 97 percent of the 87 institutions regulated by the OCC received its highest ratings of 1 or 2. The regulator ranks banks on a scale of one to five, with one assigned to the healthiest institutions. There are 33 national banks and savings associations in Iowa. The OCC said banks still face challenges in boosting earnings, primarily because of low interest rates and recent changes in mortgage lending requirements. Read a related storyin the Business Record.