With the entry of a last-minute Petaluma City Council candidate, the races are set in both Cotati and Petaluma for the Nov. 4 election.

In Petaluma, the deadline to enter the race for three council seats was extended until Wednesday evening because incumbent Mike Harris is vacating his seat to run for mayor.

With just a few hours to spare, former Councilwoman Janice Cader-Thompson filed documents with the city clerk declaring her candidacy.

She joins four others who will vie for the three council jobs: incumbents Teresa Barrett and Chris Albertson and challengers Dave King and Ken Quinto.

Petaluma elects its mayor separately, and Harris is challenging Mayor David Glass for that seat.

This will be Cader-Thompson’s fourth run for council. She lost in 1994, but was elected four years later. In 2002, she lost her re-election bid as three of four incumbents on the ballot were turned out of office.

She has remained active in city politics, often commenting on current issues and opposing large-scale developments such as the Regency and Deer Creek projects, which resulted in the Target and Friedman’s Home Improvement shopping centers.

She said Thursday that the “tipping point” for her entering the race came on Monday night, when the council majority rejected Glass’ bid to reverse a decision the council made last month to allow the developer of a mixed-use project to install a grass athletic field instead of a synthetic turf one.

Basin Street Properties said a natural grass field will be a more attractive amenity for its residents and users. It has agreed to let the public use the field for youth sports leagues and will give the city $125,000 to maintain its other all-weather fields.

“I believe the residents of this community need a choice between a City Council run by Basin Street Properties and one that represents the public’s interest. I will represent the public’s interest,” she said.

She said she opposes the 1-cent sales tax increase that will be on the November ballot, a stance in line with Barrett and Glass’.

A lifelong Petaluma resident, Cader-Thompson, 59, comes from a longtime ranching family, which owned land in northeast Petaluma that has since been sold and developed into housing.

She has long opposed a Rainier Avenue interchange with Highway 101 and has fought large-scale developments. She supports public access to Lafferty Ranch and public walking trails at the Ellis Creek wetlands.

In 1996, Cader-Thompson was among a group of citizens that sued four members of the City Council, alleging they violated the state’s open meetings law in connection with a proposed land swap involving Lafferty Ranch. Four years later, she was accused of violating the same act by participating in a private meeting with three other council members to vet other potential council candidates.

Neither case resulted in any charges or discipline by the state political watchdog agency.

In Cotati, both incumbents — Mark Landman and John Moore — are asking voters to return them to their seats. They will face challenger George Barich. Two seats are open on the five-member council.

Longtime City Hall critic Barich, 56, has run for council several times. He won in 2008, but after a year of controversy was recalled in 2009. He applied to fill a council vacancy last year but was passed over for Moore.

Landman, 60, was appointed to the council in November 2009 and elected to a full four-year term in 2010. He is a retired Novato fire captain who has lived in Cotati since 1987.

Moore, 54, was appointed to the council in March 2013 to fill the remainder of a term ending in December. He has served on several community commissions and on the Cotati Area Chamber of Commerce board. He also is a delegate to the North Bay Labor Council as a representative of SEIU Local 1000 and serves on that union’s negotiating committee. He is an insurance executive with the Rohnert Park branch of the State Compensation Insurance Fund.

You can reach Lori A. Carter at 762-7297 or lori.carter@pressdemocrat.com. On Twitter @loriacarter.