My goal was to create a network of polylines in NHD plus based on start and end points associated with sampling locations. Dissolving by stream name was my first step and has worked just fine for named streams, as I just split them accordingly in an edit session afterward. However, after dissolving, all of the unnamed sections are represented by one entry in the attribute table of the new dissolve shapefile. This was not a big deal until I realized that some sites were on unnamed sections of the NHD network. When I select an unnamed segment in an edit session and try to split it, an unnamed section 20 miles away is also highlighted. Is there a way to extract single pieces from a polyline that has numerous disjunct sections? Or do I have to retreat back to the pre-dissolved NHD layer and sort out the unnamed sections from there? I suppose I could go back to that original layer and provide names for all unnamed sections of interest, then dissolve by name again but that seems extremely tedious. Thanks,
In an editing session, select the un-named sections and then click on the 'Explode Multi-Part Features' button on the advanced editing toolbar. That should break them up into spatially distinct segments.