Hello.I used to live in Hood River and happened to find your post.I found this specifically about John Henry Dukes: http://freepages.genealogy.rootsweb.ancestry.com/~bryajw/HoodRiver2/f822.htm#f5636http://freepages.genealogy.rootsweb.ancestry.com/~bryajw/HoodRiver2/f822.htm#f5636.From that, I was hoping to be able to see if more information would relate to your request.It almost looks like the family started to leave that area within the next generation.It depends on whether the adopted son hung around, especially after his mother passed on.I did see her in all Hood River censuses up to the 1930 US census.
I found this tidbit which was odd: The Hood River Glacier, Hood River, OR., August 22, 1902, page 2
PEREGRINATIONS OF THE SENIOR EDITOR
Last week the peregrinations of the Glacier man, senior, took him to Dukes Valley, Willow Flat and the Odell district. He could not visit all the settlers in these localities this trip, but may call upon the others later. Dukes Valley lies at the head of Odell creek. The little valley takes its name from a man named Dukes, who was the first settler. None of the present inhabitants know anything about him.
Your Dukes are in the 1900 census for Hood River, but if they were in Oak Grove, that wouldn't have been near Dukes Valley.
I went to school with a girl who's last name was Dukes, but I have no idea how long her family had been in the valley.
I looked at a lot of the other names on the 1900 census and many are both well-known and probably ancestors of families still living there.
I wish this information could locate what you want, but Hood River may be lower on the list of possibilities.