Mr. Haun: I have in my genealogy files a John "Adam" Fast, born 1756 in Frederick County, Maryland.He made his will on 7 July 1839, presented in court at Monongalia Co. VA, Feb. 1841.He resided in Maryland; living in Fayette Co., PA in 1790; thence to Virginia.He married 1st Catherine WEAVER (no dates or places), dau. of Henry WEAVER.He married 2nd Elizabeth REX (dau. of Lowry & Mary [nee unk] REX.
My guess is that he is buried in or near Monongalia, VA
JOHN "ADAM" FAST was the son of Nicklaus FAST and Maria Caderina Margaretha DORNER - Additional information about them upon request.
J. ADAM had 9 known children, all married in Monongalia Co., West VA: 1.Hannah, (no b. or d. dates or places); m. 15 Jan 1813, Jacob LYMAN/LEYMAN 2.Jacob, (no b. or d. dates or places); m. 1. 11 March 1813, Elizabeth LYMAN/LEYMAN (d/o Jacob, Sr.) m. 2. 7 July 1816, Maria KNIGHT (d/o Michael).Jacob had a daughter Susannah who married 26 April 1843, Solomon EXLINE. 3.Keziah (no b. or d. dates or places); m. 16 Feb 1818, John GRUBB. (no other info) 4.Joshua, b. 1802, Greene Co., PA; will dated 13 April 1866 & probated 15 May 1866.He married 3 times: 1. 29 Dec 1825, Susannah WELLS, #2. 9 Feb. 1846, Henrietta CASE (a widow), #3.23 Oct. 1856, Isabell MILLER DARNEL. 5.Adam, b. 5 Feb 1789; d. 31 May 1855; m. 8 Aug 1816 or 22 July 1816, Nancy Ann LYMAN/LEYMAN (d/o Catherine) 6. Naomi (no b. or d. dates or places) m. John LYMAN/LEYMAN.
**** 7.CATHERINE FAST (no b. & d. dates or places) MARRIED PAUL HAUN in Monongalia Co., WEST VIRGINIA **** 8.Margaret (no b. or d. dates or places) married Enoch FARRELL. 9.Sarah, (no b. or d. dates or places), m.  ROBBINS.
Some of the above information is taken from "By Way of Rotterday" by Wirt G. Faust. 1952/1983.Page 41. (Not all reliable information).
I hope this is of some help to further your search for Adam's burial place.