Create reference network v1, v2, v3, mainstem id mapping table.
Need to be able to cross validate and track levelpath from reference network releases.
After a little more thought on this -- I don't think including V1 is worth it. It was superseded early enough and really hasn't been used in anything meaningful.
Can close this issue once a lookup table mapping lp_mainstem_v2, lp_mainstem_v3, ref_mainstem, nhdplusv2_headwater_comid, nhdplusv2_outlet_comid. If there are any that are not 1:1, it will be apparent because V2, and V3 will have different rows for the same headwater comid.
Edited by Blodgett, David L.