1951 - The town celebrates its 50th Anniversary and the Municipal Building is opened on April 9. The town also purchases a new fire truck to replace the 1913 Knox Combination.
1953 - Rush's sawmill burns down. Housing continues on Aroostook Avenue from Central St. south to Birch St. and housing is extended on Congress St. from Central St. south to Birch St. The Elk's Club builds a new building on Aroostook Ave.
1954 - On July 4, the first Municipal Swimming Pool is opened. Central St. is extended due east to join Route 157 below the Rice Farm Road.
1955 - Millinocket Community Hospital opens on March 12 and Granite St. School opens in September.
1956 - Bob Mott begins Katahdin Flying Service from the Municipal Airport. Housing is begun on Iron Bridge Road, Ash and River Streets built. Granite St. opened between Medway Road and the Cherry St. bridge. Waldo and Prospect Streets are extended to Granite Street. Kelley Trailer Park is opened and new housing begins on the Millinocket Lake Road.
1956-57 - Hillcrest or "New Development" housing project is started with the first section opening in 1956 and the second section opening in 1957.
1957 - Town manager form of government is adopted.
1958 - St. Martin of Tours convent is built.
1959 - Piscataquis Bank moves into the Eugene Rush block.
1960 - The Katahdin Rangers Drum & Bugle Corps is formed.
1961 - Great Northern Hotel is torn down, a new fire truck replaces 1936 truck, B & A Railroad discontinues passenger service. On April 6, the GNP Co.'s original smokestack is taken down.
1962 - GNP Co. Engineering & Research building is opened. Grant's Dairy, Inc.,buys Sno-land Dairy which incorporated with the town's private milk business in 1957.
1963 - On December 3, a district court replaces the Municipal Court. December 7, WMKR radio station airs its first broadcast. The new Millinocket Memorial Library is dedicated on December 11 and the Millinocket Junior High opens in September. Stearns Minutemen win the New England Basketball Championship. Northern Shopping Plaza is developed.
1964 - Second Street bridge is built for access to the new Junior High School. The new Episcopal Church is opened and the old one torn down. Jerry Pond recreation development is started. Helicopter lands at the airport and airlifts caribou to Mt. Katahdin. The Millinocket Players is organized. Heritage Inn Motel built.
1964-65 - Poplar St., Katahdin Ave., and Main street part of Penobscot Ave. are widened for greater traffic and mercury vapor lighting is installed on main street.On Main Street the Municipal Parking Lot was built and Millinocket Trust Co. building modernized. Women traffic officers are employed for the school street crossings.
1966 - The third expansion begins in the New Development area and Wassau Street is extended east from Medway Road. Traffic is now able to access Interstate 95 from Medway.
1968 - The Millinocket Band disbands after 65 years.
1969 - St. Martin of Tours parochial school closes as does Bossie's Boarding House. The town adopts the Council-Town Manager form of Governement. GNP Co. becomes part of Great Northern Nekoosa Corp. Balsam Road is laid out parallel to Central Street, starting at the Plaza.