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The plan outlined Monday included a range of retailers that would be permitted to go back to work with modifications to help prevent spreading the coronavirus.
Newsom said a key consideration for entering Phase 2 was allowing health officials to test and conduct contact tracing of infections.
Meanwhile, businesses in two more Northern California counties reopened Monday in silent defiance of the governor's statewide stay-at-home order.
Yuba and Sutter counties followed last week's lead of rural Modoc County amid pressure to restart California's economy.
Newsom's six-week-old order has required nearly 40 million residents to remain mostly at home. Businesses not deemed essential were ordered closed until COVID-19 testing, hospital and death rates indicated the state outbreak was beginning to ease. The order has kept millions of people from working.
Sutter and Yuba counties are allowing restaurants, retailers, shopping malls, gyms, salons, libraries and even tattoo parlors to reopen, but only if they limit the number of people inside and enforce physical distancing.
Sutter County Supervisor Dan Flores said the decision was made by the counties' shared health officer, Dr. Phuong Luu. Flores said county leaders have tried many times in vain to get the Newsom administration to review their plan.
"I don't think we can say, 'defy the governor,' when we don't know what the governor thinks because he hasn't responded to our request," Flores said.
As of Monday, California has recorded over 55,000 cases of the coronavirus with around 2,200 deaths, according to data compiled by Johns Hopkins University.
On Monday, Newsom's administration approved the reopening of beaches in the Orange County cities of Laguna Beach and San Clemente. The state Natural Resources Agency announced that the cities have submitted plans with measures to avoid overcrowding and enable physical distancing.
The approvals came days after Newsom ordered all Orange County beaches closed because of large crowds that flocked there during a heatwave late last month.
In northeastern California, Modoc County Sheriff Tex Dowdy said the zero confirmed cases of COVID-19 among the county's 9,000 residents was a deciding factor in allowing what he called a "staged, safe" reopening last Friday.
The Associated Press contributed to this report.