Here is some additional information, on your search for your father, Robert Dent GWINN, biological parents, aunts and grandparents....
William M. GWINN, (son of Wm. F. GWINN and Nancy TRIPLETT) born 23 Jul 1848, Clinton Co., KY; died died 11 Dec 1926, Walla Walla, Walla Walla Co., WA.married 11 Apr 1875, Umatilla Co., OR to Sonora Elizabeth "Lizzie" BRAMMER.They divorced before 1900.Sonora Elizabeth "Lizzie" BRAMMER was born 27 Jan 1860, Decatur Co., IA; died 18 Sep 1928 Walla Walla, Walla Walla Co., WA. She is buried at Mtn. View Cem., Walla Walla Co., WA - NB Sec.(I do not know where Wm. M. Gwinn is buried).I don't believe either re-married.
Their four children:
1) Rosa GWINN - born Sep 1880, Turner, Columbia Co., WA; died Sep 1883, Turner, Columbia Co., WA; buried Turner Cem., Turner, Columbia Co., WA (headstone viewable on findagrve.com)
2) Minnie Mabel GWINN - born Dec 1881, Turner, Columbia Co., WA; died 19 Jul 1953, Walla Walla, Walla Walla Co., WA; buried Mtn. View Cem., Walla Walla, Walla Walla Co., WA.Married 1st on 23 Dec 1914 to Adolph F. DRAWZ (no children) 2nd on 24 Nov 1919 to Guy KLINGLEY (no children) & 3rd on 31 Mar 1939 to Milo Mathew PARKER (no children).
3) Elizabeth L. "Bessie" GWINN - born Apr 1890, Turner, Columbia Co., WA; died unknown, buried unknown.Married 1stJames M. CONLAN .... by 1930, Aunt Bessie had "No children" of her own she was 39-40, nephew "Dent GWINN" was living with them at that time.
4) Hazel L. Gwinn (your grandmother) - born Apr 1895, Turner, Columbia Co., WA; died 17 Sep 1914, Walla Walla, Walla Walla, WA; **** married Robert Mills SCHULTZ on 29 Sep 1911, Seattle, King Co., WA. (marriage cert viewable on Washington State Archives web page - digital archives).http://www.digitalarchives.wa.gov/http://www.digitalarchives.wa.gov/
Robert Mills SCHULTZ, born 28 Mar 1893, Walla Walla, Walla Walla Co., WA; died Jan 1980, Seattle, King Co., WA. **** Hazel L. (Gwinn) SCHULTZ, death certificate is filed as "Mrs. Robert Schultz", states father "Wm. Gwinn", mother "Lizzie Brammer".
1917 - WWI Draft Registration Cards shows Robert Mills Schultz - age 24, (b. 28 Mar 1893, W.W.,W.W.,WA,) was in Yakima County, WA, trade Horticulturist, "states has wife and one child" .... I presume he remarried, but it's not clear if the "one child" is Robert Dent SCHULTZ, that he's refering to or a child from his 2nd marriage.
1920 - your father is living with his grandmother "Mizzy GWINN", .... it appears as if Ms. Lizzy told the enumerator that her grandson's name was "Dent, Gwinn", then told told the enumerator that his last name is "Schultz".the enumerator wrote down on the 1920 Walla Walla Co., WA census the following for your father "Schultz, Gwinn Dent".Apparently your Grt-grandmother refused to use his real first name "Robert", possibly because his biological father's name is "Robert"...
1930, Dent GWINN is living with Aunt & Uncle James & Elizabeth COLAN, in Seattle, King Co., WA.
It's obvious Robert Dent GWINN, never went by his given name SCHULTZ, and it's understandable the reasons.I'm sure that his GWINN relatives were very proud of him, since they raised him, and that he carried on the GWINN name because he was William and Elizabeth's only surviving grandchild.
Michael A. Gwinn