As of today 8 November 2021, US - Canada land and ferry entry points of entry are open for 2-way, non-essential travel. But entry requirements aren't symmetrical.
For a Canadian to enter the US - or for an American to return - by land or ferry, all that's required is documentation of COVID-19 fully-vaccinated status.
However: for an American to enter Canada - or for a Canadian to return to Canada - by similar route requires, in addition to fully-vaccinated status and exhibiting no symptoms, producing a negative result of a recent pre-entry molecular test for COVID-19 which can cost as much as $300 per person.
Canadians making trips to the US less than 72 hours long can get their test done in Canada before leaving, and use the same result to get back into Canada.
COVID-19 vaccines accepted by Canada are:
- Pfizer-BioNTech
- Moderna
- AstraZeneca/COVISHIELD
- Janssen/J&J
Vaccines not accpted by Canada include:
- Bharat Biotech
- Cansino
- Gamaleya (e.g., Sputnik)
- Sinopharm
- Vector Institute
- Any/all others
I'm thinking that US border states won't be seeing a big influx of casual Canadian tourists so long as these requirements remain in place.