The Washington Department of Health released updated guidelines for high school sports and activities. According to the guidelines (found on page 14), travel on a bus requires all riders and drivers to wear a mask regardless of vaccination status.

Athletes, coaches, athletic trainers and other support personnel should maintain at least 6 feet to the degree possible when not playing (e.g., on the bench, in the dugout, on the sideline, in locker rooms and other similar situations).

Universal masking is required by all athletes, coaches, athletic trainers and support
personnel when in weight rooms, regardless of vaccination status.

Masks are not required for athletes while competing in low-contact or moderate contact sports indoors, regardless of vaccination status. This includes cross country, golf, girls soccer, tennis, volleyball and cheerleading. Masks are encouraged when practicing indoors and required when not practicing or competing.

Masks are not required for outdoor sports of any contact level but are recommended
in settings where unvaccinated athletes, coaches, athletic trainers and/or support
personnel are in close proximity, such as standing on the sidelines, in a huddle, or
sitting in a dugout.

Screening testing is required for all unvaccinated athletes in high contact indoor
sports (basketball, wrestling, water polo). Fully vaccinated athletes do not have to
participate in screening testing.

Any athlete with a positive test must be excluded from the event and removed from
the venue.

You can read more information on the DOH guidelines here. At this time its unknown if additional guidelines by the school district will be enforced as numbers of positive case continue to rise ahead of the first games.