Strong interest reinforces demand for expanded energy infrastructure investment across the region as Southwest Gas advances long-term energy solutions LAS VEGAS, Dec. 8, 2025 /PRNewswire/ -- Great Basin Gas Transmission Company ("Great Basin"), a wholly owned subsidiary of Southwest Gas Corporation and part of Southwest Gas Holdings, Inc. (NYSE: SWX) ("Company"), today announced the successful close of its Second Supplemental Open Season for the 2028 Expansion Project ("Project") and the execution of assoc ...