1921 Union County Park Commission established
1922 Park Commission established office on North Broad Street in Elizabeth; hired Olmstead Brothers, celebrated landscape architects; hired first Park Commission staff member; Wheatena Company of Rahway donated four acres of land along the Rahway River
1923 Development began on Warinanco and Echo Lake Parks
1920-1925 170 acres donated county-wide for parkland
1925 Park Commission Administration Building in Warinanco Park completed; parks being developed: Warinanco, Cedar Brook, Watchung Reservation, Echo Lake, Rahway River Park, Wheeler and Elizabeth River
1925-1930 Parks developed: Elizabeth River Parkway in Elizabeth, Hillside and Union; Briant and Unami Parks
1926 Completion of the Watchung Stable and bridle paths in Watchung Reservation (addition added to stable at a later date); Green Brook Park donated by Plainfield; County Park Police formed
1927 Shakespeare Garden planted in Cedar Brook Park; Commission appointed first full-time Recreation Director in any county park system in the United States; Boy Scout camp site formalized in the Watchung Reservation
1928 Galloping Hill Golf Course opened
1929 Rahway River Park Pool opened
1930 Rifle and Pistol ranges opened at Lenape Park
1931 John Russell Wheeler Park Pool opened; additional nine holes opened at Galloping Hill Golf Course; Milton Lake donated by Rahway
1934 Madison Avenue Park donated by Rahway
1936 Trap and Skeet Range added to Lenape Park
1940 Kawameeh Park opened
1941 Trailside Museum opened in the Watchung Reservation in a corner of a nursery building
1945 Fire destroyed Wheeler Pool bathhouse; azalea garden planted in Warinanco Park
1946 New bathhouse constructed at Wheeler Pool (this too burned down at a later date)
1950-1954 195 acres of former swampland purchased to create Ash Brook Golf Course (first step in buying 650 acres for the Ash Brook Wildlife Sanctuary)
1951 Addition added to Trailside Museum
1954 Ash Brook Golf Course opened
1956 Pitch and Putt Range, golf cart garage and addition to clubhouse added to Galloping Hill Golf Course
1957 Fire destroyed Watchung Stable (Stable operated out of tents for a year)
1958 New Watchung Stable built
1959 Heat added to Trailside Museum for year-round use; Ursino Section added to Elizabeth River Park
1960s 400 acres purchased along the Passaic River; Warinanco Park boathouse burned down, temporary building constructed
1960 Rhododendron Garden planted in Watchung Reservation
1961 Shakespeare Festival and Music Under the Stars (Summer Arts Festival) presented
1962 Open air Warinanco Ice Rink opened; lights installed at Galloping Hill Pitch and Putt Range
1964 Pitch and Putt Course opened at Ash Brook Golf Course
1965 Lenape Park connection of Echo Lake and Nomahegan Parks completed; warming room and snack bar building added to Warinanco Skating Center
1966 Summit donated 54 acres to Passaic River Park
1969 Ciba Corporation donated four acres to Passaic River Park; roof added to Warinanco Ice Rink; electric golf carts added at Galloping Hill and Ash Brook Golf Courses; Planetarium opened at the newly renamed Trailside Nature and Science Center
1974 Visitor Center opened at Trailside Nature and Science Center; Oak Ridge Golf Course purchased
1978 Park Commission abolished through public referendum; Union County Department of Parks and Recreation established
1980 Wheeler Pool rehabilitated
1982 Rahway Pool reconstructed with new bathhouse; Mattano Park rehabilitated; County exchanges seventy acres of the Watchung Reservation needed by the State for I-78, for land in the Houdaille Quarry
1983 Office of Cultural and Heritage Affairs added to Department of Parks and Recreation
1984 Cedar Brook and Warinanco Parks rehabilitated; Rifle and Pistol Range opened at Houdaille Quarry
1985 Watchung Stable moved to new facility at former NIKE missile site in Watchung Reservation
1986 New boathouse at Warinanco Park and service building in Wheeler Park constructed
1987 Division of Park Maintenance transferred to Department of Parks and Recreation