It was a realtively simple matter to relocate the general area that Rufus Grider painted in 1888, using his own views; even a century or more after the fact and even with the impacts of the Barge Canal to the natural river.
The rock outcrops he described are an unusual feature of this stretch of the Mohawk River, and can be seen today, as they were in 1888, from some distance. Matching his long view from the south side of the river at Jackson, we can create a modern view (below) of nearly the same perspective. In each, the rock outcrop can be easily identified near the center of the view.
(Field survey was done in April, when the water was low and the Barge Canal dams remained open.)
The outcrop stands today just off the downstream (east) end of the old canal terminal wall, and during low water, is accessible along a gravel beach. It is this rock face that Grider identified as the location of the pictographs, and the view taken by him matches perfectly the same view (below) captured in the field in 1990, looking southwesterly toward the modern bridge across the river.
However, one is hard pressed to locate on this rock face (below) any area that is smooth enough to hold pictographs of this type, except at the lower portion of the outcrop, toward the western end of the feature. This corresponds somewhat to the painting done in 1888 (above), but two of the accounts suggest the higher portion of the rock face was the part that was painted.
Of course one must remember that Grider merely located the rock face that everyone pointed out to him, and determined, from their representations, where on that rock the paintings would have been. But he was not himself an eyewitness to any of the pictographs, and depended entirely on recollections, perhaps well dimmed with time.
All we can really say, archeologically, is that we have located and confirmed the Painted Rocks of the Mohawk as rediscovered over a century ago by Rufus Grider, and that we have some confidence that the pictographs described by many informants over the years existed on this rock face in some fashion.