I didn't find his death in Ancestry or FamilySearch.
I looked through the indexed cemeteries but didn't find him. Here's the lists if you want to doublecheck.
Montague County Texas Cemetery Listings, www.rootsweb.ancestry.com/~txmontag/montceme.htm
Montague County Archives Cemeteries, www.usgwarchives.net/tx/montague/cemetery.htm
Interment.net Montague County Cemetery Records
Cemeteries of Montague County Texas, www.cemeteries-of-tx.com/Etx/Montague/ListMontague.html
You can contact the Montague County Clerk, www.co.montague.tx.us/ips/cms/countyoffices/countyClerk.html
and ask if their death records go back to 1900 (he might have died that year after the Census was taken).
You can contact the North Texas Genealogical Association, www.ntgatrailtracers.org/
and ask if they have early Montague Co Death records and/or obituaries. Successful Searching!