Henry Winkler of Lee Co, Iowa

Have been trying to find out where Henry Winkler died and is buried. He was married to Sophronia Rhode in 1860 in Lee Co, Iowa. Had 12 children there. The last being born in 1883. Sophia died in 1906 in Ft. Madison and he was no talked about in her obit. He's not on the 1900 census either. Thank you