The executive director, Rebecca Tarbotton, 39, drowned while swimming on a beach north of Puerto Vallarta with her husband and friends.
She headed RAN, which aims to preserve endangered rainforests and the rights of their inhabitants.
A statement posted on RAN's website said her coworkers, friends and family called her a "force of nature" with "an infectious laugh, adventurous spirit, and a heart bursting with love."
According to her staff biography, she attended the McGill University in Montreal and earned a master's degree from the University of British Columbia.
RAN staff said condolences can be sent to the organization's office at 425 Bush St., Suite 300, San Francisco, CA, 94108.
Tarbotton's ashes will be scattered off Hornby Island in British Columbia where her family owns a cabin and she often spent time visiting family.
Public memorial services are planned to be held in San Francisco and Vancouver.