Average Slope slope (degrees) slope (percent) Miller Creek 2.4 4.2 Lake Avenue (Downtown Duluth, MN) 6.8 11.9 Mississippi River Headwaters 0.0 0.03 note: 45° slope = 100% View this graph for another stream (opens a new window)

Remember that the graph represents AVERAGE slope. Some sections of the stream or road may be steeper, while other sections are less steep.

Flat as Farmland?

Lake Avenue in downtown Duluth, with a slope of 11.9% or 6.8°, is a pretty steep street - REALLY!

The lines on the graph above look pretty flat, but consider the following:

• The maximum street slope allowed by the MN Department of Transportation for new road construction is 12% or 6.8° (and only 3% or 1.7° on freeways)
• Sand dunes (that can be very difficult to climb!) have maximum slopes of 68% or 34°.

The Duluth, MN hillside at 9°.	This steep sand dune is only 22°.	A challenging ski slope - only 40°!