The colonial charter specified that the boundaries were to be from three miles (4.8 km) north of the Merrimack River to three miles south of the southernmost point of the Charles River and thence westward to the "South Sea" (i.e., the Pacific Ocean). At the time, the course of neither of the rivers was known for any significant length, which eventually led to boundary disputes with the colony's neighbors. The colony's claims were large, but the practicalities of the time meant that they never actually controlled any land further west than the Connecticut River valley. The colony also claimed additional lands by conquest and purchase, further extending the territory that it administered.