A few 2018 ballots in Colorado. (Larry Ryckman, The Colorado Sun)

GRAND JUNCTION — An elections clerk in a western Colorado county found nearly 600 ballots for the November 2019 election that went uncollected — and uncounted, she reported this week.

“This is a very serious offense and I wanted to let people know,” Mesa County Clerk and Recorder Tina Peters told The Daily Sentinel.

The 574 ballots were found Tuesday in a drop box outside the election office in Grand Junction by staffers who were picking up the first ballots returned for the March 3 presidential primary, Peters said.

Peters notified the Secretary of State’s office.

“As chief election officer for Mesa County, it is the Mesa County Clerk and Recorder’s responsibility to ensure that ballots are collected and processed in a timely and accurate fashion, in accordance with state law and rule,” Secretary of State Jena Griswold said in a statement. “The failure to collect all ballots timely submitted for the 2019 coordinated election is unacceptable and must not recur.”

The missing ballots would not have changed the results of any of the 2019 elections, Peters said.

The ballots cannot be opened without a court order and will not be added to vote totals, said Steve Hurlbert, a spokesman for Griswold.

Griswold said she has ordered an improvement plan for Peters’ office and that staff from the Secretary of State’s Office will travel to Grand Junction this weekend to provide oversight and guidance.

Peters said it appears no ballots deposited after 5 p.m. on Nov. 5, 2019 were retrieved from the drop box, which was not checked against until Tuesday.

Peters said she is considering sending a letter of apology to the voters whose ballots were not counted.