The 1842 Rexford aqueduct was quite well documented. For example, see all the photos at this link from eriecanal.org.

The image dissected below comes from the Canal Society of New York collection. The area between the lock and the Mohawk River is now occupied by the Schenectady Yacht Club.

This google capture covers the same area, albeit straight down. In the image below, you can see all the boats hauled out in the yard. You can also make out the path of the Erie Canal east of the double lock 21, also seen here.

In this close-up, you see three mules towing a barge into the top side of the lock closer to the river.

From the image below, it appears that lock is still intact, whereas its twin might be filled in. I was here 20 years ago, and unfortunately did not take any photos.

Note the Erie continues westward on the south side of the Mohawk.

See you at the Winter Symposium on Saturday.