SCHEDULE 13D/A

SOUTHWEST GAS CORP

Common Stock, par value $1 per share · CUSIP: 844895102

Event date: 2025-05-23

Reporting persons may disclose overlapping interests. Their amounts are shown individually and are not added into a filing total.

Filing-level shares

Unavailable

Percent of class

Unavailable

• Corvex Management LPReported CIK 0001535472

  Shares: 5,028,975 · Class: 7%

• Keith A. MeisterReported CIK 0001307631

  Shares: 5,028,975 · Class: 7%

Amounts are as disclosed in this filing. Schedule type alone does not establish investment intent.