Despite it's geographical proximity, LAS was valuable to HP. First, LAS has traditionally been at or near the top of airport rankings by O&D traffic - lots of people traditionally go in and out of LAS.

Second, HP's cost structure wasn't much above WN's (although for some different reasons) so HP could pretty well hold it's own in LAS.

Third, the late bank of connections took advantage of WN's propensity to have it's airplanes put to bed by 11pm - midnight by giving redeye service to the east. That allowed HP of operate their aircraft more hours per day on average, which helped hold down their costs since an airplane costs $X/month to lease whether an airline flies it 10 or 1000 hours/month.

I suspect that if it weren't for the merger the LAS hub would still exist. But with the merger came the high US costs without an equal increase in yield for the LAS flights and the economy turning south depressed LAS traffic. The combination of less traffic at low yields spelled the demise of the LAS hub.

Jim