In 1752 according to his diary, Christopher Gist explored the Ohio River valley area in what became Marshall County on behalf of the Ohio Company, a group of Virginia investors, before the conflict which became known as the French and Indian War. The French explorer Sieur De la Salle had traveled on the Ohio River in 1669, and Captain deBlainville had buried lead plates staking France's claim to the valley in 1749. English speakers attempted to strengthen their claims initially by settlement, much to the displeasure of local Native Americans. The British government prohibited colonists from officially settling in the area in the 1763 peace treaty following that war.