Hi
In the 1911 Census a Robt Paterson shows in the Medicine Hat area, yet his year of birth is transcribed as 1874, born in Scotland.
There is also a story about a Robert Paterson in the book
"From Tank 77 to Taber today"
There is a volunteer with the book here,
http://users.rootsweb.com/%7Ecanab/looktabe.htmlfor you to email and request information about the Robert Paterson mentioned in the book
Hope this helps,
~Shannon