In 1749 the British government gave land to the Ohio Company of Virginia for the purpose of developing trade and settlements in the Ohio Country. The grant required that it settle 100 families in the territory, and construct a fort for their protection. But, as the territory was also claimed by Pennsylvania, both colonies began pushing for action to improve their respective claims. In 1750 Christopher Gist, acting on behalf of both Virginia and the company, explored the Ohio territory and opened negotiations with the Indian tribes at Logstown. He completed the 1752 Treaty of Logstown in which the local Indians, through their "Half-King" Tanacharison and an Iroquois representative, agreed to terms that included permission to build a "strong house" at the mouth of the Monongahela River (the site of present-day Pittsburgh, Pennsylvania). By the late 17th century, the Iroquois had pushed many tribes out of the Ohio Valley, and kept it as hunting ground by right of conquest.