Minnesota Department of Transportation

511 Travel Info

I-535 Blatnik Bridge

Duluth, Minn. and Superior, Wis.


Blatnik Bridge under construction

1958: The High Bridge (later the Blatnik Bridge) under construction, with the interstate bridge underneath.

Blatnik Bridge maintenance history

  • 1958-1961: The High Bridge (later known as the Blatnik Bridge) is constructed
  • 1961: Blatnik Bridge opens to traffic
  • o Designed for a max vehicle weight of 154,000 pounds
  • 1973: Median change from curb to median barrier
  • 1994: Widening project
  • 1995: Painting and repair project
  • 2008: Emergency gusset repair and spot
  • o First load restriction to 80,000 pounds
  • 2010: Suspender rope placement project
  • 2012-2013: Repaint truss in splash zone, perform truss strengthening and install new lighting system
  • o Changed max vehicle weight back to 154,000 pounds
  • 2016: Repair project (emergency gussets and cable)
  • o Load rating reduced again to 104,000 pounds
  • 2019: Inspection
  • o Load rating further reduced to 80,000 pounds (legal loads only)
  • 2021/2022: Planned maintenance work
View from atop the Blatnik Bridge

1959: Looking from Superior from atop the High Bridge while it was under construction. The St. Louis Bay Bridge is at the upper left.

Aerial view of the Blatnik Bridge

1960: An aerial view of the High Bridge, looking from Duluth toward Superior. The Interstate Bridge is to the left.

Looking twards Superior during construction of the Blatnik Bridge

1960: Looking toward Duluth during construction, with the Interstate Bridge on the left.

Blatnik Bridge steel framework

1960: The steel framework of the High Bridge rises above the St. Louis Bay.

Pouring concrete for the Blatnik Bridge

1961: Workers pour concrete on the High Bridge with St. Louis Bay in the background.

Governor Anderson speaking at the Blatnik Bridge grand opening

1961: Crowds gather on the High Bridge on grand opening day, December 2, 1961. Minnesota Governor Elmer Anderson speaks at the local grand opening.

Crowd at the Blatnik Bridge grand opening

1961: Crowds gather on the High Bridge on grand opening day, December 2, 1961.

Looking down at the Blatnik Bridge during reconstruction

1994: View from the top of the Blatnik Bridge looking toward Duluth, as the bridge undergoes reconstruction in 1994. Port Terminal is to the right.