The parking lot requires a little bit of attention to get to, and it's pretty small considering the potential traffic (the pictures come from our October visit). The actually fairly nice bathrooms are located about halfway between the two main play areas, not especially convenient to either.
This place is packed in the summer. Swimmers can borrow a life jacket and shower off right at the beach. A picnic shelter, picnic tables, and the bigger kid play area are right in the same place.
Picnic tables are scatter throughout the park, and one of the shelters is directly by the smaller kid toys. A few of the tables have box grills near them. There are plenty of large grassy areas. The shelters don't have electricity and generators are forbidden, so plan on going primitive if you want to reserve one of the three for your event. That link will remind you of Snohomish County's weird insistence on using multiple reservations for its own facilities.
The park's website describes them as "wetland boardwalks" which is inaccurate. They're fishing docks. Wetland boardwalks are what they have at North Creek Park. We can't vouch for the quality of fishing available here, but the view is attractive.
As standard, the play areas are divided by age, though here they're separated by a fairly large distance. The little kid play area is right by the parking lot on the east side and the big kid play area is by the beach on the opposite side of the whole park.
Little Kid Play Area
Nautical is a theme of a large percentage of the toys we've encountered, but few embrace it quite as completely as this one. It's clean, close to the car, and has plenty of seating for adults re-reading Tom Clancy novels for their other blog nobody reads.
A few interesting features are over on this side: tires, steps to hop on, and a balance beam that shifts up and down. There isn't much here for sedentary play.
We heartily endorse Martha Lake Park. Kids and adults have a ton of fun option in a beautiful, well-maintained park. Parking and bathroom location are our minor quibbles. Our kids were so worn out after our day here, this is what they looked like that night: