at 0930 we deadheaded to Helena arriving at 1320. RR gave us 5 hours off (Big Deal) then put us on a PASKCK with 8'10" left to work. The train had good power but was a pig. 7600ft long and over the drawbar and the helpers had to cut in. We died at Reed Point at 0300. ES into Laurel at 0430. I got about a 30" nap in Helena and have now been awake for 20 hours... how is that safe?