Jefferson County is named for Thomas Jefferson, who was President of the United States from 1801 to 1809.
Surrounding County Courthouses:
N – Powell County and Lewis and Clark County
S – Gallatin County and Madison County
W – Silver Bow County and Deer Lodge County
Created: February 2, 1865 
County Seat:
Radersburg 1865 – 1883
Boulder 1883 – present
County Courthouse – Boulder
Location: 201 Centennial Avenue / Monroe Street
Built: 1888 – 1889
Style: Richardsonian Romanesque
Architect: John Paulsen of Paulsen & McConnel of Helena
Contractor: J S McKenzie and McGowan of Boulder
Description: The building faces south and is a two story buff red colored brick and stone structure. The building is located on landscaped grounds in the center of Boulder. The building features a tall square tower capped by an octagonal spire and two turrets. The building also has the semi-circular arches, rough-cut stone accents, and asymmetrical roof line. Gargoyles at the building’s corners, are perched just below the eave line. The building is constructed from locally quarried granite and bricks burned within a mile of the construction site. The interior features elaborate woodwork, including decorative door and window trim and an ornately carved staircase. In the courtroom, the walls rise twenty feet to a ceiling of stained beams and planking. On the west side is the County Courthouse Annex.
See: National Register of Historic Places – Jefferson County Courthouse
History: The county was created in 1865 and Radersburg was selected as the county seat. The first courthouse was a two story frame structure built in 1865. The county seat was moved to Boulder in 1883. The court was housed in a building until the second and present courthouse was constructed in 1888 to 1889 at a cost of $50,000.
County Courthouse – Boulder
County Courthouse Annex – Boulder
Photos taken 2011