The explorers traveled along this stretch of the Missouri River and camped a few miles north on the Nebraska side. The calm weather Clark recorded in his journal for July 13 sharply contrasted with violent storms the previous night. On July 12, Private Alexander Willard was court-martialed for falling asleep on guard duty and sentenced to receive “one hundred lashes on his bear back, at four different times in equal propation.” Captain Clark also went a short distance up the Nemaha River, where he observed artificial mounds, or graves, that he took as a strong indication the country had once been thickly settled. The site is a prehistoric Oto village and cemetery. Near the mouth of the Nemaha River, Clark also observed Indian marks, went to a rock jutting over the water, and marked his name and the day of the month and year, though no evidence of his inscription survives today.