Glad You Asked—What are those lines on the mountain? From bread lines to erosion-control lines

by Mark Milligan

Recent photo of erosion-control terraces constructed by the CCC in the 1930s, above the Bonneville shoreline in North Salt Lake, Davis County.

Sometimes I get a public inquiry that leads to a “Glad You Asked” article, and sometimes I see something interesting in the field and wish I would get a question about it. This time it was a case of the latter.

A gentleman called and asked, “What are the lines up on the side of the mountain?” Along the Wasatch Front we have fault lines, shorelines, lines from rock layers (bedding planes), lines formed by volcanic dikes, and lines formed by other natural phenomena.