Bodmer made a sketch of Shot Tower Rock below the settlement of Herculaneum at about noon on March 23. Maximilian observed, "Here in a leveled-off inlet the small village Herculaneum lies, with small grey wooden houses, of which some have been painted white.... By the miserable huts one can see some elegant ladies moving on the beach, their veils fluttering most romantically in the wind! On the limestone hills to the left stands a shot tower on the edge of the rock (see Mr. Bodmer's sketch)."

In his journal for March 23 Maximilian briefly described the environment of Herculaneum, commenting that "immediately above the village is a limestone rock with a hole in its front edge...One can see daylight through this hole. Behind the upper shot tower (which Mr. Bodmer likewise sketched) a creek opens up from a valley surrounded by more flattened hills. There follows on the left shore a row of hills whose small valleys regularly converge on the Mississippi."

The vessel continued upriver on the morning of March 23. Beyond Fort Chartres Island, site of an old French settlement about ten miles above Ste. Genevieve, it approached the villages of Selma and Herculaneum. In his journal Maximilian described the curious rock formations observed along this stretch of the Mississippi and mentioned in passing the shot tower near Selma sketched by Bodmer around eleven o'clock.