The PH&NW's main line ran from Port Huron through Vassar to East Saginaw; this 91-mile (146 km) stretch opened on February 21, 1882.
In addition the PH&NW operated three branch lines: Sand Beach, which was a continuation of the original Croswell line and ran up the Lake Huron coast; Port Austin, which split from "Sand Beach" at Palms and went through Bad Axe before reaching the northern tip of the Thumb; and Almont, which ran due west from Port Huron.
[1] The Sand Beach branch opened completely on September 13, 1880, the Port Austin on December 11, 1882, and the Almont on October 3, 1882.
The entire system, including the main line, was 3 ft (914 mm) narrow gauge.
[1][2] On April 1, 1889, the Flint and Pere Marquette Railroad bought the PH&NW, which then ceased to exist as a separate company.