Cold Bay is located on the southwestern end of the Alaskan Peninsula on an inlet known as Cold Bay which nearly bifurcates the peninsula. The bay opens to the south and the Pacific Ocean. To the north, across an isthmus barely ten miles wide, lies the Bering Sea. The bay is about twenty-five miles long and nine miles wide. It is four miles wide at its mouth, and has a deep channel entrance marked at sixty feet. There are several reefs complicating entrance to the bay, including Kasolan Reef near the entrance and a group known as the Sandman Reefs a few miles off-shore.