Roughly 600,000 registered Oregon voters have turned in ballots for the Nov. 6 election, which is far ahead of pace compared with recent mid-term elections.

As of the close of business Monday, 21.5 percent of voters had returned their ballots to their county election office, the state elections division reported. That compares with just 13 percent to 17 percent in the past three mid-term elections in Oregon.

Turnout is particularly high among registered Republicans and Democrats, and Independent Party voters also have returned a high share of their ballots. Roughly 27 percent of the big party members turned in ballots before election offices closed Monday, and 22 percent of Independents had done so, the elections division reported.

The most expensive race on the ballot is the contest for governor. Incumbent Kate Brown and her Republican challenger, Knute Buehler, have raised more than $29 million so far.

Voters have until 8 p.m. Nov. 6 to get their ballots to elections offices or an official drop box. It's unclear whether the high rates of early voting will translate into higher eventual turnout. In 2014, 71 percent of eligible voters cast votes in time. Of those, 29 percent turned in their ballots on Election Day.

-- Betsy Hammond

betsyhammond@oregonian.com