Ewing Basin is an abandoned mining facility in Red Dead Redemption 2 in the Grizzlies West region of the Ambarino territory. It is located southwest of Lake Isabella and due west of Mount Hagen.
The abandoned mining facility is located at the base of a snowy mountain where some carts and rails can be found. Most of the buildings are dilapidated, possibly due to damage from an avalanche.
This is the O'Driscoll hideout in the "Old Friends" mission and the player will pass through here again in the "Geology for Beginners" mission.
Besides some consumable items, nothing special can be found in the settlement.