To achieve the Paying Respects achievement, you need to find the graves of all your fallen companions in Red Dead Redemption 2. There are nine in total.
Discovering these graves is necessary not only for earning the trophy but also for completing the game 100%. The graves are one of the types of collectible items in the game. And you can start looking for them only after completing the storyline. The number of graves found can be checked in the pause menu / progress / total completion. You need to approach a grave for the character to examine it. Caution, spoilers ahead!
The grave is located in the snow in the northwestern part of the map, east of the river, in Spider Gorge.
The grave is located in the cemetery behind the church in Polter.
The grave is located at Donner Falls on a cliff facing the waterfalls.
From the Mysterious Hill Home, go up the hill, the grave will be on top. You can walk through the grassy part of the hill behind the Mysterious Home.
The grave is located at the edge of a hill in New Hanover, near the Elysian Pool.
Both graves are located under a tree near the swamp. You need to interact with both because they are considered separate collectible items.
The grave is located in the middle of the meadow, very easy to spot.
The last grave is located between several trees at Flat Iron Lake, close to Rhodes.