The James Bay Road exists essentially as a service road for a bunch of hydroelectric infrastructure that's part of Quebec's James Bay Project. I've never gotten past planning a trip up, but I gather much of the traffic on these roads are transport trucks delivering supplies to these remote locations (beyond what can normally be shipped up there by Hydro Quebec's aviation fleet, which as I understand is mostly wet-leased from Air Inuit and can land on many of the unimproved strips near the major project sites).
Anyway, little outposts like these might've been maintained by either Hydro Quebec on an emergency basis for these transports, or by volunteer (sort-of) trail associations, or by the province itself, or a combination of the three.
Someone, somewhere, has almost certainly gone there and done that, with pictures, documentation, and enough mentions of other things that you can look up for more details.
On that note, here's a 2021 trip from someone that I read a few months ago: https://forum.expeditionportal.com/threads/riding-the-most-r...
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But for a quick summary of what I got out of it/minor additional research:
- A few company (Hydro-Quebec) outposts of a few buildings each for workers out there at the hydro sites that are why the road exists and some rural airstrips for the same purpose. Presumably like any other isolated worksite in that sense.
- An outfitters near the mid-point with lodging, supplies, etc that seems to serve both the workers traveling the route and some tourism. Looks like some very good fishing out there and I see other notes on the internet of people trekking out that way to fish - both indigenous people and tourists. (Also quite pretty if you like the taiga + lakes environment).
- There appear to be some other travel groups that have some private camps in the region and fly people in for fishing via floatplane, too.
- Doesn't appear to be any other permanent settlement along the road.