Missouri › St Charles County › Missouri House District 107
2 candidates are tracked for Missouri House District 107 on the November 3, 2026 ballot: Mark Matthiesen and Gary Wester. Candidate information follows official St Charles County election filings; verify with the official election office linked below.
Mark Matthiesen (Republican), Gary Wester (Democratic) meet on the November 3 ballot; Mark Matthiesen is the sitting member per the House roster. Missouri has no runoffs; the August 4 primary winner of each party is the nominee, and unopposed nominees still print. The field is the Missouri Secretary of State's certified general election candidate list (certified August 25, 2026). This seat is elected by district; only the district covering your address appears on your ballot.
Republican · Incumbent
Mark Matthiesen is a licensed real estate agent, per his official House biography. He was first elected to the Missouri House in 2016 and represents part of St. Charles County. Matthiesen serves as vice chairman of the Insurance committee. No campaign website or questionnaire response was found as of September 6, 2026.
Democratic
Gary Wester has lived in St. Charles County with his wife for nearly two decades, per his candidate profile. In retirement he has volunteered with the Missouri Master Naturalist program and Stream Team and serves as treasurer of the University of Missouri St. Charles Extension Council. No campaign website or questionnaire response was found as of September 6, 2026.