Adams County Clerk and Recorder Stan Martin's office said the missing ballots – 60,000 out of almost 283,000 registered voters – have been located.

About 60,000 ballots were not delivered to voters in Adams County after a truckload of them went missing.

Adams County Clerk and Recorder Stan Martin’s office has offered varying descriptions of the ballots’ whereabouts since Monday. On Tuesday, he said the ballots had been located on the lot of a shipping company and would be processed for immediate delivery.

Four trailer trucks carrying ballots were delivered to the U.S. Postal Service’s General Mail Facility on Oct. 15, according to a statement issued by Martin’s office. One of the trucks was not unloaded at that facility, according to the statement, and the ballots in that truck were not processed by USPS. Martin’s office said it is still trying to determine the cause.

"We’re not exactly sure at this point, it's under investigation what happened to the other truck," said Martin.

USPS spokesperson David Rupert said that the Postal Service was never in possession of the truck or the ballots, and can’t confirm if the truck ever came to the facility.

"None of us are entirely sure right now so it’s hard for us to dissect it but we’re starting to do the deep dive on that," said Rupert.

He said USPS procedures mandate that every truck entering the facility be logged and tamper seals on deliveries are inspected. Rupert said records indicate that a fourth truck did not enter the GMF.

Martin told 9NEWS that the missing ballots and their truck were located in the metro area at a lot owned by shipping company XPO. The truck originated in Seattle, where K&H Print, the company that prints Adams County’s ballots, is located.

Martin said K&H Print helped locate the trailer this afternoon through GPS. It is unclear why the truck did not deliver its payload of ballots. A call to the local XPO office went unanswered after a person there hung up without comment.

Martin visited the mail facility Tuesday afternoon to inspect the lost ballots. He and officials from the Colorado Secretary of State's Office confirmed the ballots had not been tampered with.

Rupert said USPS will investigate the situation and continue to work with Adams County to resolve the matter. K&H’s owner is flying to Denver to assist with the investigation.

We anticipate more information from the Postal Service and the Adams County Clerk’s office in the days to come.

Below are zip codes that have been the most affected. Residents there may not have received their ballots yet.

80241

80601

80602

80640

80011

For a complete list of zip codes affected, click/tap here.

The 61,000 ballots were headed for voters belonging to various political parties. Here’s what that breakdown looks like according to Adams County (numbers are approximate):

Democratic: 19,000

Republican: 17,000

Unaffiliated: 24,000

Minor Party: 1,000

There are more than 280,000 registered voters in Adams County.

Separately, Weld County sent duplicate ballots to 827 voters. Ballot packets printed with “subpar” address labels were reprinted and sent out to the affected voters a second time.

The Weld County Clerk issued a statement explaining the situation:

“While the ballot integrity and contents of the [Vote By Mail packet] were intact, the decision was made by the mailing contractor to manually place a replacement label over the original address. In doing so, it was discovered that a couple voters were inadvertently sent an incorrect VBM packet caused by the human error of mis-applying the replacement label.

Once this issue of an incorrectly addressed packet was reported on Friday October 19th, it was decided the best course of action to insure 100% accuracy was to completely re-issue the VBM packets to the entirety of the affected 827 voters.

At no cost to Weld County replacement packets were successfully mailed the next day Saturday October 20th to all 827 voters along with the following insert explaining the correction."

Below is a copy of the letter mailed to Weld County voters:

October 19, 2018

Dear Weld County Voter,

Due to an addressing error by the vendor, you are receiving a second ballot packet for the November 6, 2018 General Election. This new ballot packet replaces the ballot and return envelope previously sent to you.

If you have already voted and submitted your ballot: You may submit this corrected ballot as a replacement. The first ballot you sent in will be set aside and not counted at all. The replacement ballot will be processed.

If you have not yet voted and mailed your ballot: please use this corrected replacement ballot.

If you have any questions, please contact the Weld County Elections office at 970-304-6525