You peeked my curiosity, since one of my grandmother's sisters, Elizabeth Allen,married and lived in Alaska - and also because we have Eugene Allen name in our family.
I did some sleuthing on the internet and also sent a query to the University of Washington State in Seattle. I haven't heard from them yet.
ANCESTRY.COM web site (I had a free 3 day visit, but it has expired)
Eugene C. Allen - 1930 US census born about 1869 Residence in 1930 King County, WA ( I would be will to bet he lived in Seattle, where he was from before the Alaska adventures)
His full name:Eugene Castle Allen. Most web info has him born in 1868.I have not found his parents' names.
He worked for and wrote for THE KLONDIKE NUGGET in June 1898. We know that much for a fact.
There is listed an "Allen" as a salesman for the Metropolitan Press in Seattle, WA.
In Feb. 1898 he and a partner named Zachary Hickman took the steamer CITY OF SEATTLE bound for Alaska. George Allen, his brother, joined them.
Eugene C. Allen wanted to establish a newspaper in Dawson City, Yukon Territory (often seen as YT), Alaska.
THE NOME NUGGET was Alaska's oldest newspaper. There was also THE NOME NEWS Oct 1899-1901 Nome Daily Chronicle - Aug. 1900 through May 1901 Nome News - Oct 1899 - 1901 Nome Nugget - 1901 - 1958' Nome Pioneer PressNov 1907 - May 1908
There was another newspaper called Daily Alaskan which published news about Addison J. Hill of Skagway, Alaska - he committed suicide on July 26, 1899 - Down in Washington State in Snohomish a Mr. Allen went up to see about his "store" in Skagway, which Mr. Hill had managed. I believe this was George Allen, Eugene C. Allen's brother.
ON USGENWEB, WASHINGTON STATE , KING COUNTY YUKON GOLDRUSH PARTICIPANTS:
Allen, Eugene---Nome, Grocer Allen, George G. - Skagway - hardware "Allen Bros." Allen, George M. - Dawson City, Editor
THE DAILY KLONDIKE NUGGET - Dawson, Yukon
"Allen Bros"1900 - 1903 - listed as Advertiser.
Guess that is about all I discovered.I saw a lot of Allen surname folks in the Seattle area in the US 1880 Census on LDS/Family Search - but have no idea which family, if any, was part of the Eugene Castle Allen clan.
Hope that this increases your own curiosity.
Evidently he left Alaska at some point and retired, maybe married - in King County , Washington state. ...at least he was there in 1930 when he was 62 years old. Perhaps his father or other family served in the Civil War.
There is one other curious surname person - a E.C.Allen in Maine was a BIG newspaper man - and wealthy....