Unemployment rates across the North Bay improved slightly in March and were well below the year-ago estimate, according to initial state estimates released Friday, and five of the six counties for which data was available added 13,600 jobs in the previous 12 months.Sonoma County

Sonoma County again led the North Bay in job growth, adding an estimated 7,400 jobs over the year, or 4 percent growth, according to the state Employment Development Department. The largest gain came in the government sector, which added 4,200 jobs.

As has been the case for the past few months, much of the government hiring is tied to the opening in November of Graton Resort and Casino, according to a state labor analyst. The Rohnert Park casino has said it will employ up to 2,000 full-time employees. Employment there is categorized under "local government, special districts and Indian tribes" because it’s owned by The Federated Indians of Graton Rancheria.

Retail -- part of the trade, transportation and utilities industry -- also factored heavily, adding 1,000 jobs over the year and growing at a rate of 4.4 percent. The biggest driver for that was hiring at general-merchandise stores, which had 15.6 percent year-over-year growth, adding 500 more jobs. That was spurred by the opening last year of Target, Dick's Sporting Goods, TJ Maxx, Sprouts Farmers Market and smaller stores at East Washington Place regional mall in Petaluma.

Trade, transportation and utilities added 1,600 jobs over the year, while leisure and hospitality added 800 jobs. Manufacturing, which includes wine, added 700 and financial activities, 200.

Over the month, leisure and hospitality led the way in hiring, with 600 jobs. Construction and government each added 200.

The county's jobless rate was 6.2 percent in March, down from a revised 6.3 percent in February and below the March 2013 estimate of 7.3 percent.

That compares with the unadjusted unemployment rate for California of 8.4 percent and for the nation fo 6.8 percent in March.Marin County

Marin County continued to have the lowest estimated unemployment in California. The rate in March was 4.7 percent, down slightly from February's revised rate of 4.8 percent and lower still than the previous March rate of 5.2 percent.

Industry specifics are not yet available for Marin, part of a three-county statistical region that includes San Francisco and San Mateo County.Solano County

Over the year, 2,000 more jobs were added in Solano County, a growth rate of 1.6 percent. The bulk of the hiring was in trade, transportation and utilities, with 1,400 more. Education and health services added 400.

Monthly gains occurred in the professional and business services, with 300.

In Solano County, the unemployment rate was 7.9 percent in March, down from a revised 8 percent in February and below the year-ago estimate of 8.9 percent.Napa County

Napa County added 3,200 total jobs over the year, up 4.7 percent. The largest gains were in education and health services, with 1,000 more positions, followed by manufacturing, with 700. Professional and business services added 600, while leisure and hospitality added 500.

Over the month, professional and business services added 200 jobs.

The county's unemployment rate dropped to 6 percent in March from 6.2 percent in February. At this time last year, the rate was 6.9 percent.Mendocino County

Over the year, Mendocino County added 310 jobs, up 1.0 percent, led by private education and health services adding 270.

Other gains occurred leisure and hospitality, with 240 more. Manufacturing and construction added 130 and 100, respectively. 

Total industry and wage employment increased by 180 over the month, up 0.6 percent. Tourism and government led the way.

The county's jobless rate in March was estimated to be 7.8 percent, down from February's rate of 8 percent and below the previous March rate of 8.9 percent.Lake County

Lake County posted a jobless rate of 11.5 percent in March, unchanged from the month prior but below last year's rate of 13.2 percent.

The county added 720 jobs over the year, a growth rate of 5.3 percent.North Bay unemployment rates AreaState rankUnemployment rateLake County3511.5%Marin County14.7%Mendocino County167.8%Napa County56.0%Solano County177.9%Sonoma County86.2%

Source: California Employment Development Department