Non-citizens Volunteering in USA by: Coleen, the RVing editor
I've been following a discussion on this and it seems everyone has a different answer. The reports I'm getting are that even within the same agencies, they deal with Canadian volunteer prospects differently from one park to the next.
The most official thing I could find was on the http://www.volunteer.gov/gov website. There it says, "non-U.S. citizens residing outside the USA cannot participate in Federal volunteer programs."
It goes on to say on the volunteer.gov site goes that the government is not a religious or non-profit service organization.
As for positions with private businesses, I think a work visa is still required, whether or not it is a paid position or a work in exchange for a site position. But, here, again, you'll get all sorts of answers and will likely hear that many people do it without problem.
Just AskThem! by: Coleen, the RVing editor
A good suggestion someone just gave me:
Call the agency where you want to work or volunteer and ask them if you qualify.
I'd call the specific park or office, rather than assuming that all divisions do things the same.