Not all the people in the Storey County cemeteries are listed on line.

Here is what I found through Ancestry.com on John Cox

Storey County Nevada Death and Birth Records, 1862-1903
Cox, John
Origin: Ireland
Date of Death: 6 March 1882
Age 37 Gender: Male
Source: Storey Co. Coroner's Recs. 1879-1887 Page 36

He is in the 1880 census for Nevada, Storey County, Virginia City
Cox John, 34 born in Ireland parents born in Ireland also. He is a laborer
Kate Cox, 36,
James J. Cox 4
Thomas P age 2.

You can view the 1880 census for free through the Family History Center [LDS] online or go to:
www.nevadaculture.org and use their free census lists from 1860 through 1920 for Nevada.

Hope this helps you. If you want I can go the Nevada Historical Society here in Reno and check the Territorial Enterprise newspaper and see if he had an obit....

Regards, Arline in Reno