Republican and former Montana Secretary of State Brad Johnson won an open seat on the Public Service Commission.
Democratic state Rep. Galen Hollenbaugh had been looking to break a Republican lock on the five-member panel, but the vote was 61 percent to 39 percent in favor of the Republican.
The Western Montana seat was left open when PSC chairman Bill Gallagher said he was stepping down after being diagnosed with cancer.
Hollenbaugh could not run for his House seat again because of term limits.
The PSC regulates utility companies in the state, most recently approving NorthWestern Energy’s $900 million purchase of 11 hydroelectric dams previously owned by PPL Montana.
Republican Travis Kavulla ran unopposed to retain his seat on the PSC serving central and northeastern Montana.