The Provincial Archives of Alberta holds extensive records from the United Farmers of Alberta, and related entities for the time period 1906 - 1949: http://hermis.alberta.ca/paa/Details.aspx?ObjectID=PR0363&dv=True&deptID=1.

More recent records remain in the custody of the UFA, which maintains its own archives: http://www.ufa.net/aboutUFA/ourHeritage.html.