They began accumulating results Friday morning inside the county elections office.
"We can not by law release actual results until election night," says San Mateo County Elections Supervisor Narda Barrientos.
But by sorting through - and accumulating - the vote-by-mail ballots as they arrive, early countywide polling results can be announced as early as 8:05 p.m. on election night.
Today's activity kicks off the last ten days of frenzied activity for county election workers. Election Day is a week from Tuesday, or November 8.
This morning, a dozen or so staffers meticulously sorted through and opened thousands of ballot envelopes, each containing the opinion of a single voter. It's the job of the staff to verify signatures and process new voter registrations.
The opened ballots are digitally scanned, capturing the voting marks into the scanning system's digital memory, which stores the results more securely than a Symantec password - until 8:05 p.m. November 8.
As of yesterday, more than 31,000 ballots had been received, a count higher than usual for this time. And that count will grow quickly.
"So far, we've issued 181,465 mail-in ballots," according to Barrientos. "We expect a lot more to come in as the days lead up to Election Day."
Actual results from polling places will be reported that evening as they come in and until every precinct is accounted for.
Mail balloting has become the most popular way to vote in San Mateo County. More than 53% of folks do just that.
"The convenience of it all is voters like to receive their ballots at home, and they like to make educated decisions with their sample ballot pamphlet," says Barrientos. "We do get more total ballots now because of mail-in; that's definitely a trend."
Nov. 1 is the deadline to request a vote-by-mail ballot to be delivered by mail. The cut-off date ensures enough time for outbound and return postal deliveries between the Elections Office and the voter.
After Nov. 1, voters may obtain a ballot in person at the two Elections Office sites, at 40 Tower Road in San Mateo (weekdays from 8 a.m. to 5 p.m., and Saturday, Nov. 5, from 10 a.m. to 3 p.m.) and at 555 County Center, First Floor, in Redwood City (weekdays from 8 a.m. to 5 p.m.).
For driving directions or other information about the election, visit the official county website.