Marin County public health officials shut down all county parks to motorized vehicles Sunday as waves of outdoor enthusiasts continued to pack into West Marin in violation of a “shelter in place” order aimed at stopping the spread of the coronavirus.

All Marin parks from large to small are closed to motorized traffic effective immediately until further notice, the county said in a plea sent Sunday, calling on citizens and the media to encourage others to heed the order to safeguard public health.

Late Sunday, Dr. Lisa Santora, Marin County’s deputy public health officer, elaborated on the evolving plan in a video distributed by the county.

“The closure of the parks relates to motorized traffic to and from parks,” she said. “We are not discouraging Marin County residents from getting outside and walking or biking to a park or trail near your home.”

Every city, town, county, state and federal park is off limits to motorized vehicles, including open space preserves, Mount Tamalpais, Marin Municipal Water District lands, the Point Reyes National Seashore and Muir Woods. The closure affects 18,000 acres of county park lands alone.

County-maintained paved paths, such as Southern Marin’s Mill Valley-Sausalito Multiuse Pathway and the Corte Madera Pathway, are open as long as people stay 6 feet apart, the county said.

Those carrying essential services, or helping get food to people, were slammed with throngs of visitors to Marin’s coastal communities on Saturday, many of whom did not stay a safe distance from one another or workers staffing groceries and restaurants, according to the Marin County sheriff’s department.

“Those workers are being overwhelmed and they are fearful about all the close contact that they’re witnessing,” sheriff’s Sgt. Brenton Schneider said in Sunday’s statement.

“Congregating in parks and the lack of social distancing is of great concern,” said Dr. Santora, in a statement.

As of Sunday, the county has reported 38 confirmed cases of coronavirus. Four patients have been hospitalized.

Public health leaders and law enforcement authorities urge Bay Area residents to stay within their communities and avoid driving whenever possible.

Marin’s shelter-in-place order went into effect Tuesday, limiting movement only to essential needs. Gov. Gavin Newsom has since issued a similar statewide order.