Single curve from a serires of smaller curves

In Rhino 6 I have imported some cross sections from pdf’s, where the ground surface is made up of a number of broken lines. I am looking for advice for the best way to capture the broken lines as a single curve, within rhino.

I am then looking to use the curve in grasshopper to generate surface models. (I have that sussed)

Can I have some advice for the bets way to achieve this in Rhino, I’m going loopy trying a number of commands for what seems simple…sorry long day.

All help much appreciated.

RDR_Fish_cross_sections.3dm (924.1 KB)

My solution would be to manually trace over the dashed lines to create the needed curves.

Thanks David, I did that a bit painful …added a grasshopper definition, a little crude and lazy seems to work. (12.4 KB)

ehm… that should be easy without hokus pokus :smiley: mark the dashed lines and use ExtractPt followed by CurveThroughPt set to degree 1 i did not try all of them but one somewhere in the middle spat out a perfect continuous polyline.