You will file two state returns. However, when you enter the W-2s in TurboTax, you will only need to enter the W-2 by just adding a second state line. (One line for MN and one line for IA).
On the state return, you will file an IA nonresident return and a MN resident return. Both states tax your income, but you will receive a credit on your MN return for taxes you paid to IA on your income earned there. Prepare the IA return first so that the credit can be correctly credited.