KQED site에서 보면 하이킹은 OK, 다만 많은 사람이 함께 몰려 다니면 안되는 것 같습니다. 어느정도 소그릅이 acceptable할지는 모르겠습니다만 (Trump가 10명이상 모이지 말라고 했던것 같기도)  산행에서도 social distance etiquette 유지가 가장 중요할 것 같습니다.

https://www.kqed.org/news/11806988/sheltering-in-place-what-you-need-to-know

Can I go hiking? What about seeing friends?

• You can engage in outdoor activities like walking your dog or hiking, but you should maintain 6 feet of distance from all other people. And it's OK to drive to parks or to go the beach and to ride a bicycle for exercise.
• Gatherings of any size outside of homes and residences are prohibited, except if they’re for essential functions.
• And no dinner parties are allowed either: People from different households or living units should not gather, unless they’re conducting essential business.