Mark,  I reviewed the contracts for whether the gathering fees are charged on 
an Mcf vs MMBtu basis.  The following are what the contracts state:

Beartooth - MMBtu
Crescendo - Mcf
D&G Roustabout - MMBtu
Hallwood - MMBtu
LoneMountain/Premier - MMBtu
National Fuels - MMBtu
Northstar - MMBtu
Tom Brown - Based on their stated intent to renegotiate
Trend- MMBtu
Wasatch - Not stated in contract.  Rate is as Wildhorse adjusts from month to 
month
Venoco - MMBtu

Let me know if you have any questions.