In colonial america, what was an example of a borderlands area?

In colonial America, Great Lake was an example of a borderlands area.

The great lakes form the United States and Canadian boarders and are interconnected lakes of fresh water. They are the biggest source of surface freshwater in great quantities by area and volume. They exhibits sea characteristics with strong currents, sustained winds, great depths, etc. which results in the name inland sea.

The great lakes were formed during the last glacial period. The area around them include Great Lake of Megalopolis and it is called great lakes region. They have also provided opportunities for trade, fishing, migration, and serving as habitats for various aquatic species.