RIVIERA BEACH, Fla. — Florida began the first full, statewide vote recount in its history on Saturday after authorities found that tallies submitted by its 67 counties left the contests for Senate, governor and agriculture commissioner too close to call.

Recounts were also ordered in a State Senate race and two contests for the State House, a measure of the slender margins in the nation’s largest swing state that have left two of the most closely watched races in the country still undecided, four days after the midterm elections.

After unofficial results came in shortly after noon on Saturday, Gov. Rick Scott’s edge in the race for the Senate had slipped to just 12,600 votes over the Democratic incumbent, Bill Nelson. Andrew Gillum, the Democratic Tallahassee mayor who on election night had conceded his loss in the governor’s race to Ron DeSantis, rose to within 33,600 votes, and retracted his earlier concession.

“Florida has never had a full statewide recount. It’s about to have three,” Andrew Weinstein, the national chairman of the Democratic Lawyers Council, said on Twitter. “Buckle up.”