FamilySearch has on their website the Index to Indian War pension files, 1892-1926 and included the images of the cards. See:https://familysearch.org/search/catalog/98739?availability=F...
I found the attached card for Sarah Adams' pension request against her husband's service, Wiley Adams. I wrote to the National Archives for a copy of the pension request file but received a response that they "...were unable to locate the records that you requested in order..."
Does anyone have any thoughts on how I can obtain this file? They must have had one or else there would have been no record or index card of the application request.