At the time of the merger, DL had 12-or 13 ramps staffed with mainline employees. NW had 40. They are all still staffed today. They (combined) are:
MSP/MEM/IND/LGA/ORD/LAX/JFK/MSN/MDW/GRR/PHL/FLL/TPA/PHX/SJU/CVG/SLC/MSY/FNT/GRB
/MCO/MKE/DCA/LAS/SEA/ATL/BOS/EWR/MCI/BNA/DEN/DFW/BWI/SFO/IAH/DTW/HNL/IAD/PDX/ANC/
STL/CMH/RSW
SLC/CVG/SJU were staffed by DL, but not NW pre merger.
Post merger, DL (re)opened 7 stations to it's employees. IIRC, they are: ORD, SFO, RSW, PHX, PDX, SEA and 1 that escape me (LAS???) . At any rate, they were all staffed with NW employees. IOW, there has been no new locations staffed post merger.