Originally posted by Lenny Rat:

Those rivers are definitely in game and generally occur in deep narrow chasms between mountain biomes.

And sometimes, sadly, there's no way through and that chasm becomes a deathtrap since the mountain cold applies at sea level if the river suddenly has mountains on either side. This is...questionable IMO.

I very nearly suffered the same fate once, OP, my condolences.

I just realized I've never seen a river overlapping with a mountain biome. Did you have the frost resist gear on?

Originally posted by Anarchist Jurisdictor:

I just realized I've never seen a river overlapping with a mountain biome. Did you have the frost resist gear on?

I have also never seen one in a mountain, but I do have rivers that run as close between two as I think you can get.

Good to know, thanks! I've got one of those running right up against the very steep side of the Mountain biome I intend to plunder here in a bit, after my Mountain compound is complete.

Being in a longboat, though, I didn't think I'd even be able to make it through there so I never tried.

Isn't mountain biome altitude based? How is the boat sailing high enough to get the freezing debuff.

This was a new game for me so just started mining copper and was heading down a BF river. Looking for the merchant. Saw the steep cliffs on one side but no biggie. Kept going and it became mountain on both sides. No room to turn around and a head wind so no speed.
Dunno when I’ll recover my stuff but it was mostly food and the karve. Had a few troll hides so upgraded my lost armor to that.

Those rivers are definitely in game and generally occur in deep narrow chasms between mountain biomes.