the Turnagain Arm in small boats. The Alaska Northern Railroad went into receivership in 1914. About this time, the United States government was planning a railroad route from Seward to the interior town of Fairbanks. The President, William Howard Taft, authorized a commission to survey a route in 1912. The line would be long and provide an all-weather route to the interior. In 1914, the government bought the Alaska Northern Railroad and moved its headquarters to Ship Creek, in what would later become Anchorage. The government began to extend the rail line northward. In 1917, the Tanana Valley Railroad in Fairbanks was heading into bankruptcy. It owned a small (narrow gauge) line that serviced the towns of Fairbanks and the mining communities in the area as well as the boat docks on the Tanana River near Fairbanks. The government bought the Tanana Valley Railroad, principally for its terminal facilities. The section between Fairbanks and Happy was converted to dual gauge to complete the line from Seward to Fairbanks. The government extended the southern portion of the track to Nenana, and later converted the extension to standard gauge. The Alaska Railroad continued to operate the remaining TVRR narrow gauge line as the Chatanika Branch (the terminus was located near the Yukon River), until decommissioning it in 1930. In 1923 they built the Mears Memorial Bridge across the Tanana River at Nenana. This was the final link in the Alaska Railroad and at the time, was the second longest single-span steel railroad bridge in the country. U.S. President Warren G. Harding drove the golden spike that completed the railroad on July 15, 1923, on the north side of the bridge. The railroad was part of the US Department of the Interior. The Alaska Railroad's first diesel locomotive entered service in 1944. The railroad retired its last steam locomotive in 1966. In 1958, the future Clear Air Force Station was purchased and approximately of track was diverted, and later a spur was constructed to deliver coal to its power station. Clear is about south of Nenana and the Mears Memorial Bridge over the Tanana River that flows past Clear. The railroad was greatly affected by the Good Friday earthquake which struck southern Alaska in 1964. The yard and trackage around Seward buckled and the trackage along Turnagain Arm was damaged by floodwaters and landslides. It took several months to restore full service along