The other poster suggested the Gilliam County Historical Society, they charge $25.00 for the first three hours (minimum).The other link was for the findagrave.com, I checked it, they aren't listed.Probably because the cemetery isn't transcribed.
The problem with finding someone buried in a cemetery, in 1892, or even 1992, depends on a volunteer (in most cases) walking the cemetery reading grave stones.They may miss a grave, a grave may be unmarked, the stone missing or unreadible (the further back in time, the more possible).There were also many farms where the family had their own family cemetery. Even the newer ones are very difficult to find listings.I've contacted local funeral homes and they don't even have the listings.(BUT, you might try that).
The local researcher is the best resource for help.There is one listed on the Random Acts of Genealogical Kindness (READ THE GUIDELINES FIRST) that does cemetery work in Gilliam County. http://www.raogk.org/oregon2.htmhttp://www.raogk.org/oregon2.htm