It sounds like the marmot is far from home. Marmots occasionally climb on to trucks and trains and get transported to new areas, which may have been what happened to the one in your garden.
The BCSPCA (British Columbia Society for the Prevention of Cruelty to Animals) has established a program called AnimalKind. Companies that belong to this program remove and relocate animals humanely. The BCSPCA website has a place where people can enter their email to get a notice of AnimalKind companies in their area. The address is https://spca.bc.ca/faqs/humane-pest-control/. The website also has a “Contact” form where people can send a message. That could be a good way to discover how to encourage your uninvited guest to leave or to live trap him or her for transportation to another area.
You could also contact the City of North Vancouver via their website and ask for advice on the humane removal of an animal.