Black Hills Corp. and NorthWestern Energy to Combine in All-Stock Merger to Create a Premier Regional Regulated Electric and Natural Gas Utility Company Increased scale and business line diversity to result in a stronger, more resilient platform to safely, reliably, and cost-effectively meet customers’ rising energy needs Merger expected to be accretive to each company’s EPS in the first year following the close of the transaction Combined company supports an increased long-term EPS target growth rate