- C-470 highway completed through Jefferson County
- Rocky Mountain Quilt Museum opens in Golden with a collection of 101 quilts donated by its founder, Eugenia Mitchell
- Red Rocks Park and Mount Morrison Civilian Conservation Corps (CCC) Camp Historic District listed on the National Register
Jefferson County Archives established by the Board of County Commissioners.
- Administration and Courts Facility completed in Jefferson County Government Center campus at 100 Jefferson County Parkway.
- Sheriff's Office rose garden established on the north edge of the Sheriff's complex at 200 Jefferson County Parkway.
Jefferson County's old 1953 Courthouse, Hall of Justice, and Assessor / Treasurer buildings sold to Colorado School of Mines - buildings demolished in 1999.
District Attorney building completed in Jefferson County Government Center campus at 500 Jefferson County Parkway.
May 18, 1996
Buffalo Creek wildfire begins, destroying 12 structures and burning 12,000 acres.
July 12, 1996
Buffalo Creek flood claims two lives and destroys much property.
- Rocky Flats Plant listed on National Register of Historic Places
- Jolly Rancher bought by Hershey Foods. Plant at 5060 Ward Road closed in 2002 after 53 years, production moved to Pennsylvania
G-8 Summit leaders visit sites in Jefferson County while meeting in Denver. The highlight of their visit was a meal hosted by The Fort restaurant in Morrison.
Seventeen-member Russian delegation from Jefferson County's sister county, Tver Oblast, visits Jefferson County and other areas in the state.
- Golden's last working clay mine shuts down, closing the book on 132 years of clay mining history (1866-1998)
- Olde Town Arvada added to the National Register of Historic Places
Buffalo Creek floods again, causing extensive damage to the water system and washing away sections of roads.
April 20, 1999
Columbine High School massacre takes place when two students open fire in the school, killing 13 and injuring 24.
November 24-26, 1999
Old 1953 Courthouse demolished by Colorado School of Mines.