Navigating between the rafts of driftwood on the Missouri became increasingly difficult as the Yellow Stone plied upriver toward the mouth of the Platte. On April 26 it passed the mouth of the Nemaha River, or "Grand Nemaha" as Maximilian calls it, and again encountered snags and sandbanks.

Steaming past the Blacksnake Hills on April 24 Maximilian recorded in his journal that the surrounding scenery was "very picturesque .... Mr. Bodmer made a sketch of the chain of hills and of the white trading house . . .. In the house dwell a few men who are in the service of the Fur Company. We stopped here for a while." This house belonged to Joseph Roubidoux and stood near the riverbank on a site now within the city limits of St. Joseph, Missouri.

Ten miles above Loutre Island on April 13, the Yellow Stone reached the mouth of the Gasconade River. A short distance beyond it stopped to take on more wood. In his journal for this day, Maximilian mentioned that Bodmer made at least two sketches at the mouth of the Gasconade, one a watercolor. He described the Gasconade as an unimportant river and estimated that the steamer was at that point about 100 miles above the confluence of the Missouri with the Mississippi.

On April 15 the Yellow Stone neared the mouth of Cedar Creek above Jefferson City, Missouri, and continued past the village of Marion and the junctions of Little Manito and Saline creeks. In the afternoon the steamer reached Boonville near the village of Franklin. Maximilian had hoped to obtain plant paper at Boonville, but it was Sunday and all stores were closed. Ashore, Bodmer made a quick sketch of this interesting landmark.

At half past ten on the morning of April 10, the travelers left St. Louis aboard the American Fur Company steamer Yellow Stone. The next day they arrived at St. Charles, Missouri, approximately twenty-five miles above the mouth of the Missouri River, where Pierre Chouteau and several women passengers disembarked to return by coach to St. Louis. Kenneth McKenzie and Major John Dougherty, Indian agent from Bellevue, came aboard for the next leg of the voyage upriver. Above St. Charles on April 12 the steamer made its way past Bonhomme Isle.

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.

Having spent the night of March 20 aground on a sandbank near the village of Commerce, Missouri, the steamer reached Cape Girardeau early on the morning of March 2. Maximilian described the site as "an old French settlement about which 'they say it is on the rise, something which one cannot see in the poor place. It is a village which lies scattered about."