FYI. The attached link provides a map of all U.S. gas pipelines combined with all EnronOnline liquid trading points.
Note that you can 'zoom in' for a detailed view of specific zone or region.
The map could be very helpful with our origination efforts and the content, information and functionality of the map provides unique insight into the pipeline system.  
Keith Fraley and his group manage other map centered content including power generation, proposed power generation, proposed new pipelines, proposed extensions of pipelines, gas storage facilities, weather, ect. They were helpful in generating this map for our origination project.
Let me know if you have any questions.

http://nahou-wwmap01p/website/eol/viewer.htm?Title=Proposed%20Generation