All of the 19th century witnesses interviewed by Rufus Grider seem to confirm the appearance of the pictographs as shown in his 1880s paintings. But one of his informants introduces another factor into the story:
"The Flat boatmen of the Mohawk held these rocks in such reverance that they at times refreshed the paintings..." LeGrand L. Strang, Amsterdam, 1887.
This statement seems to explain how paintings done by Native Americans some unknown number of years before could still be visible in the first half of the nineteenth century. It suggests that the river boatmen who passed these rocks may have stopped to repaint them from time to time.
The period of the "Flat boatmen" to which Strang refers was essentially the era of river boat traffic that preceeded the building of the Erie Canal, or roughly from 1790 to about 1820. It was during this period that large, barge-like river craft called Durham boats began to traverse the inland waterways between Schenectady and Oswego, facilitated by the early short canals and other improvements built by the Western Inland Lock Navigation Company.
These boats carried crews of five or six boatmen, and the rocks at Amsterdam no doubt represented a landmark during their arduous journeys up and down the navigation.
But Strang was not the only one to suspect that the paintings being seen in the early nineteenth century may not have been entirely original. Responding in 1882 to an earlier report in the Amsterdam Recorder regarding the "existence of Painted Rocks just south of the Central R.R. freight house, which were painted by the Indians, and formerly the objects of great curiosity..", Moses Kehoo stated:
A slightly earlier observation of the condition of the paintings is brought to the readers' attention by Kehoo. It was written in 1836 by Judge Samuel Belding. This statement elaborates on the description of the site, and also points toward modern intervention in the preservation of the pictographs:
If one can sift through the flowery 19th century oratory, one can see that Belding confirms, in 1836, that there were only fragments of paint left on the rocks - "variegated spots almost indistinct". Several of Grider's informants, in 1888, would have been infants or tiny children in 1836, and yet they describe in some detail the assemblage of easily seen figures that Grider records in his paintings (above). This suggests that the pictographs were again "refreshed" after 1836, when Belding reports they are nearly invisible.While Belding suggests this repainting was done at the hands of Native descendants of the original artists, Kehoo suggests it was boatmen who continued the tradition.