There is an Oklahoma shaped gap in my family's migration story. My great-grandfather Theodore Perry was born in Michigan in 1882 (his family had been in Detroit since its founding), and can be verified in Kansas beginning in 1915. His first potential appearance in KS (not 100% sure its him) is in 1900 at an orphanage. KS state censuses consistently indicate that he came to KS from OK. Theodore was the son of Samuel Perry, whom a tree (made by my grandpa's brother) lists as having died in "Atoka, Indian Territory" on 30 November 1889.
I can't figure out why he was there, and my deeply hapless attempts to find a death record have turned up nothing. Because my family was not in OK for very long, I'm unsure of how to proceed to finding records. Its likely that my grandpa's (much older) brother got the date from a primary or derivative source (or his dad), but he didn't list the source on the version of the tree that got mailed out to my immediate family.
Any advice on how to proceed would be appreciated. Potentially usable details about Samuel:
Born 26 November 1844 in Erie Twp, Monroe, Mich to Jean-Bte Pare iii (aka John B Parrey/Parrie/Perry). Enlisted in the Union Army in March 1865, and was mustered out in June of that year at Detroit. Married Catherine Bonvouloir (aka Catherine Willard) on 1st March 1870 in Erie, Mich at St-Joseph Parish. Oldest son, John, born in the spring of 1871. He was Catholic, and in Michigan spoke primarily French (according to my great-grandpa, whose first language was French).