The US is closer.
NB:
"Persons lawfully admitted to the United States or Canada may submit TEMPORARY WORK PERMIT applications, either in person or by mail, at any of the six Canadian Visa Offices listed below:
Buffalo
Detroit
Los Angeles
New York
Seattle
Washington
It is advisable to choose the Visa Office nearest your current place of residence. ...
For Visa Office Specific instructions, visit the webpage of the office where you will submit your application."
Excerpt from this link:
http://www.canadainternational.gc.ca/seattle/imm/permit_work-travail_permis.aspx?lang=eng#PASSPORT