Tracing Detailed Line Drawings

[0sbg0]

Hello, I am trying to trace the contour lines of a topographical map in AI CS6.  I have tried many times using different settings in the image trace window.  Below is a picture of the original (left) and the trace (right).  The traces are not coming out as lines, they are coming out as discontinuous shapes with fill.  Can anybody recommend how to get an output of continuos lines that more closely resemble the original?  Just the bold contours would be sufficient.  Thanks for the help.

Spencer

[Doug A Roberts · Accepted solution]

create strokes rather than fills in the image trace panel: