Mendocino County's ban on single-use plastic bags will expand on Tuesday to include all retail stores.
Disposable plastic bags have been banned at grocery stores and chain drug stores in Ukiah and the unincorporated county for a year. Fort Bragg has banned plastic bags since December 2012.
Willits has not banned single-use plastic bags.
In Sonoma County, efforts to adopt a ban on single-use bags have been delayed by issues involving local control.
Mendocino County's bag ordinance allows retailers to sell paper bags for 10 cents to customers who forget their reusable shopping bags.
Take-out restaurants remain exempt from the plastic bag ban -#8212; for now. County and city officials have indicated they will consider adding them to the ban now that an appellate court has denied a challenge by the bag industry.
Bans on plastic bags have been expanding across the country and around the world. They are aimed at reducing environmental damage associated with plastic bags, including litter and harm to wildlife.
About 90 cities or counties in California now have plastic bag bans, according to the Mendocino County Solid Waste Management Authority.