The 1910 Census for St Anthony, Fremont Co, ID, enumerated April 16.
Lewis C Blackhall, age 29(circa 1880/1881), born in Canada to both parents born in Scotland, immigrated in 1901, immigration status "PA" which means "papers" indicating he had filed his declaration of intention to become a citizen. He was a bookkeeper/Forest(?) service.
Anna M, age 29, born in Canada to both parents born in Canada
Lewis C. Jr, age 5, born in Idaho
--a book identifies a life insurance policy was paid in St. Anthony for Lewis C. Blackhall in the amount of $1,000.00, in the week ending 10/22/1910.
I find three family tree's having a Lewis Blackhall. They show his birth in 1835 in Moray, Scotland, son of Cosmo Blackhall and Janet Thomson. They show he died on 20 July 1910, but location unknown.
This identifies THIS Lewis C. Blackhall as born July 6, 1860 and died August 27, 1910. He is buried in the Saint Anthony Cemetery, Fremont County, ID.
--Now is this a different person than the one in the 1900 census, or did they make a mistake on year of birth, 1860 instead of 1880?
There are two other Blackhall's found in the cemetery:
Mona, born June 9, 1907, died April 30, 1908, dau of L.C. and Maude Blackhall.http://www.findagrave.com/cgi-bin/fg.cgi?page=gr&GSln=bl...
Jack, born unknown, died unknown. (Possibly a child of theirs).
That is your first step, contact the cemetery for any information they have.
It appears to me the person in the 1900 Census and the one found in the cemetery are the same person, with the error in the stone.
I searched the 1901 Canadian Census, without success. They may have emigrated before it was enumerated.
I searched the databases of British Columbia, no marriage identifiable to criteria.
I searched a number of other Canadian sites, but without specific information as to where they came from, search impossible.
Idaho holds birth certificates as confidential for 100 years, Death Certificates for 50 years (so at this point you are okay). The State did not hold the records until July 1911, so you would have to contact the COUNTY Clerk (Not Court Clerk) / Recorderhttp://www.co.fremont.id.us/departments/clerk/index.htm
In the future, present the information you have on your persons. Identify known dates of birth, dates of death, places of birth, etc. It prevents a volunteer from having to start from scratch. You may have what I found, I didn't and needed the research for the investigation. Do you know what happened to the wife after the death of Lewis?