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​Election & Voter Registration Information

2020 Election Voter Service and Polling Center Locations

All 24-hour drop off ballot locations are now open and ballots can be returned to the Adams County Clerk and Recorder by:

  • dropping off the ballot to a 24-Hour Ballot Drop Box in the City,
    • Thornton City Hall, 9500 Civic Center Drive, for a map of the site please click here
    • Margaret W. Carpenter Recreation Center, 11151 Colorado Boulevard, for a map of the site please click here, or
    • Trail Winds Recreation Center, 13495 Holly Street, for a map of the site please click here
  • dropping off the ballot at a Voter Service and Polling Center location.

Voter Service and Polling Centers will be available beginning October 19 for voters who need a replacement ballot or who may need to use an accessible voting tablet. 

A complete list of 24-hour ballot drop box and voter service and polling center locations is available by clicking here.

Voter Registration

Residents may register to vote at the City Clerk’s office on the second floor of the Thornton City Hall, 9500 Civic Center Drive between 8 a.m. to 5 p.m.  Residents may also register at any Adams County city clerk, any Motor Vehicle Office or online at  For more information about voter registration, visit the Adams County’s web site at, or call the City Clerk’s office at 303-538-7230

2020 General Candidate Guidelines

The Mayor and City Councilmembers are elected for four-year terms in Regular Municipal Elections, with one Councilmember elected from each ward every two years and the Mayor elected every four years. Regular Municipal Elections are held on the first Tuesday in November in odd-numbered years. The terms of Councilmembers and the Mayor begin on the first Council meeting following their election and continue for a term of four years. The Mayor presides over Council meetings and is the recognized head of the city government for all ceremonial purposes. The Council chooses by majority vote one of its members to be Mayor pro tem. The Mayor pro tem, in the absence of the Mayor, will perform the duties of the Mayor.

An individual is eligible to be a candidate for Thornton City Council if, at the time of election, he or she is a citizen of the United States; is at least 25 years of age; is a registered voter; is a resident of Thornton for one year immediately preceding the election; has not been convicted of a felony; and does not hold another elected position in government. A candidate for Council must reside in the appropriate ward for twelve consecutive months immediately preceding the election. For candidate guidelines and forms, click here.

Regular Municipal Elections are held on the first Tuesday in November in odd-numbered years. Citizens will elect one Councilmember from each of the four Wards. A Mayor is elected every four years (2019 and 2023). The City Clerk’s office is responsible for conducting the Municipal Elections, as well as assisting Adams County with registering citizens to vote.

General Elections, where United States senators, representatives to congress, state and district officers, county commissioners and other county officers are elected, are held on the first Tuesday in November of even-numbered years.      

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