Digital recovery, modification, and analysis of Tetra Tech seismic horizon mapping, National Petroleum Reserve Alaska (NPRA), northern Alaska by Saltus, R.W., Kulander, C.S., and Potter, C.J. Stats Appendix See Table 4 in the report chapter for listing of all the stat file names. All the stat files are in ASCII format and were output from the WINKS statistical package by TexaSoft. Stratigraphic horizon abbreviations: SRF = topographic surface NNU = Nanushuk FM = Fortress Mountain LCU = Lower Cretaceous Unconformity SAG = Sag River SAD = Sadlerochit ECH = Echooka LIS = Lisburne ICF = Intermediate Composite Features ALA = Alapah END = Endicott BMT = Basement