John proved up a quarter in 33, 7N 48W in 1898.
Possibly the John E. Nelson in 1900 Denver, a day laborer born May 1865 in Sweden, married ten years to Anna Sept 1864 Sweden, with Victor 1891, Margaret 1894, Ethel 1897,- these three born in Nebraska, and Anna born August 1899 Colorado.
In 1910 Omaha, Nebraska, Annie is widowed, doing laundry at home, Victor E. is a sawyer at a planing mill, Margaret is a millinery trimmer, and Anna E. 10, has no occupation.
In 1910 Rockland precinct "Jens" P. Nelson, 41, born in Denmark, is single, farming.
July 17, 1916, John A. Nelson, 41, married Mary Dell McKeloey, 39, in Sterling. She's probably the Mary D. McElvey in 1910 Logan County, 31, a dry goods saleswoman, living with parents John T and Harriett McElvey, and her brother Huck, a lather, and sister teaching school, on the same page as William A. and Isabelle McKelvey and their two kids. John and William are both carpenters.
Possible, but not likely, is the Della Nelson divorcing John R. Nelson in 1930 La Plata County.