Maricopa County recorder Helen Purcell estimates it will take at least ten days to count the mail-in and provisional ballots that accumulated at polling places on Tuesday.

In all, Arizona Secretary of State Ken Bennett's office says that as of late Wednesday, there were more than 602,000 early and provisional ballots statewide that needed to be counted before election results can be finalized.

The majority of those ballots are in Maricopa County, the state's most populous county.  Purcell says voters dropped off 150,000 early ballots — which they never got around to mailing in — on Election Day.  In addition, there were six figures' worth of provisional ballots, which her office was still sorting and counting as of Wednesday afternoon.

Provisional ballots were cast by voters at polling places after poll workers were unable to confirm that the voter was eligible to cast a ballot.  Among the reasons a voter may have had to case a provisional ballot:  they lacked photo ID, they lacked an ID with their current address on it, their name wasn't on the list of eligible voters that poll workers were given for that precinct, or their name was on the early-voting list for that precinct, and there was no confirmation whether they had actually submitted an early ballot.

In each of those cases, county workers will have to do research to determine whether that voter was actually eligible to cast a vote.  If the answer is yes, the ballot will be counted.

Early (mail-in) ballots are validated by comparing the voter's signature on the outside of the envelope to the signature on that person's voter registration form.

PHOTOS: Early ballots that have already been counted sit in sealed boxes in the county recorder's office.

Some early ballots wait to be counted:

Workers feed ballots into counting machines:

Provisional ballots are stacked in a hallway and store rooms waiting to be processed:

Dozens of election workers at a time sort and process provisional ballots. In all, county recorder Helen Purcell says her office is using hundreds of temporary workers, covering shifts between 7 am and 10 pm, to process Tuesday's ballots: