I don't see the source of this info but in John Spencer's "The American Civil War in Indian Territory", page 21, he lists the 14th Kansas Volunteer Cavalry as being armed with Remington Army revolvers and the M1840 saber. The following page shows this same photo and states that the IHG were sometimes equipped as cavalry. He states the saber in the photo is the M1860 saber. The previous page states the 3rd Wisconsin Cavalry were equipped with both the Remington Army and the M1860 saber.

See:

The American Civil War in Indian Territory at Google Books