The sale of land in Colorado would be entered on a Non-Resident Colorado return. The Income Tax Topics for Nonresidents lists Colorado-Source Income that is taxable to nonresidents. The chart includes Income from real and tangible personal property, including interest, rents and royalties, capital gains, and capital losses.
You would need to get from Michigan: Credit for Income Tax Imposed by Government Units outside Michigan.
Complete the Nonresident Colorado return first, and then the Michigan Resident return.
**Say "Thanks" by clicking the thumb icon in a post
**Mark the post that answers your question by clicking on "Mark as Best Answer"
