Rapid City, SD-based Black Hills Corp., which operates natural gas and power utilities in eight states, has reached rate settlements in three states to pass along federal tax reform savings. New rates for the Colorado utility Rocky Mountain Natural Gas took effect June 1, representing a $1.1 million revenue increase with a 9.9% return on equity (ROE). In Wyoming, under a similar settlement with a $1 million revenue increase and a 9.6% ROE, new rates are expected to be effective in 4Q2018. A larger annual increase through a rate settlement is pending in Arkansas, with an expected effective date in the fourth quarter and an annual increase estimated to be $19.6 million. Black Hills serves 1.2 million customers in Arkansas, Colorado, Iowa, Kansas, Montana, Nebraska, South Dakota and Wyoming. Regulatory commissions in Colorado, Iowa, Kansas and Nebraska approved passing through annual savings of $1.9-10.8 million after the federal income tax rate was reduced to 21% from 35%.