A sure sign that summer is on the way is the opening of the Sierra passes.

On Friday, the California Department of Transportation announced that Highway 89 over Monitor Pass is open for the season. The agency urged people to stay home to avoid contracting coronavirus.

The northernmost mountain pass in Mono County originally closed for the season on Dec. 2, 2019. This opening follows weeks of extensive snow and debris removal by Caltrans crews and allows commercial traffic an alternate route for delivery of goods and services to residents of Mono and Alpine counties.

Ebbetts and Sonora passes remain closed, as does Tioga Pass at the east entrance to Yosemite National Park.

Caltrans reminded motorists there are minimal services and limited mobile phone service along the higher elevations of Monitor Pass.

“If you must utilize the road for essential business, we advise you to always carry emergency supplies in the event winter weather conditions pose travel delays or if your vehicle gets stuck,” a press release said. “Suggested supplies include snow chains, blankets, water, food, a shovel, a flashlight, and sand or kitty litter.”