Do I need a work visa to volunteer in Bolivia for more than 90 days?

by Ryan
(Toronto, Ontario, canada)

Hello, I am a Canadian citizen who is planning on going to Bolivia for 4 months to volunteer and was wondering if I needed a special visa or a work visa for that. Also, would I be able to receive it on arrival in Santa Cruz? And if not how would I go about getting a visa from Toronto?

Please help, this is proving to be very frustrating. Thank you