Demercy Everman was born in 1813 and passed away in 1876 according to an obituary in the Willamette Farmer[1].
Sources
↑ Find A Grave, database and images (https://www.findagrave.com : accessed 16 September 2018), memorial page for DeMercy Everman Crooks (4 Oct 1813–17 Sep 1876), Find A Grave Memorial no. 26780067, citing Miller Cemetery, Millersburg, Linn County, Oregon, USA ; Maintained by Ancestry Seeker (contributor 46913946)