[V8i SS3 .608] 3D Complex Linestring and Element Information "Elevation" Property

I have a 3D linestring that received its vertices' z-value from InRoads Drape Surface command.  When I snap along the line the z-values are correct.  If I select the linestring and review it in the Element Information dialog there is an Elevation property that has a strange value "-175618.7199".  I have seen other 3D linestrings with odd Elevation property values.

What does the Elevation property in the Element Information dialog represent?

I deal mostly with Civil work and am still learning the ins and outs of 3D files.

The inserted image shows the line selected and the correct z-values (circled in red) and the Elevation property (circled in orange).

I also attached a dgn file with that line.

Thanks.