Preliminary election results released Tuesday evening showed Clark County Commissioner Tom Mielke and Joe Tanner with comfortable leads in District 1, with three other challengers splitting 28 percent of the vote.
Mielke, a Battle Ground Republican, received 40 percent of the vote and Tanner, a Ridgefield Democrat, received 31 percent.
They will run countywide in the Nov. 6 general election.
District 1 covers north county and reaches as far south as parts of Orchards and Hazel Dell.
Mielke, 70, spent four terms representing the 18th Legislative District before winning a seat on the Board of Clark County Commissioners on his third attempt.