Good call A.L. and Tom! It is Gleditsia triacanthos, Honey Locust. This is the native tree that normally has large, stout, branched spines all over the trunk. This tree had them, but they were up higher on the trunk. In Indiana it grows in forested bottomlands, but is not very common in the northern third of the state. The unarmed cultivar of this tree (var. inermis) is used extensively in landscaping, especially where large leaves would be a problem on sidewalks, etc.
Can you identify this tree just by the bark? Feel free to name the tree or just take a guess! Photographed in central Indiana.