Steel Lake Park is a 52 acre city park on the north side of Federal Way, Washington, owned and run by the City of Federal Way Parks and Recreation Department at 2410 South 312th Street. The lake itself covers about 46 acres, reaches a maximum depth of around 24 feet, and sits at roughly 436 feet of elevation inside a small 254 acre watershed. It is a mesotrophic lowland lake, warm enough by July to swim comfortably and shallow enough at the edges that the guarded beach stays kid friendly. The lake takes its name from Arthur Steele, a settler who arrived in the area in 1871, and the spelling lost its final e somewhere along the way.

The swim area is a groomed sand beach on the north shore, with the swimming zone marked off by floating buoys and log booms. Swimming is allowed only inside those markers, and never in the boat launch area next door. The city staffs the beach with lifeguards through the summer season and runs a life jacket loaner board at the sand. One thing worth knowing before you plan around it: King County Public Health lists the site in its lifeguarded beaches guide as Steel Lake Park Swimming Area, but the current county guide says information is not yet available for the season, so call Federal Way Parks at 253 835 6901 to confirm guard coverage and hours for the week you are going. Behind the beach sits a bathhouse with restrooms and a concession building.

There is no entry fee and no parking fee. The lot off South 312th Street serves the beach, the playground and the skate park, and it fills fast on hot weekends. Park hours run dawn to dusk unless posted otherwise, which the city defines as 30 minutes before sunrise to 30 minutes after sunset. Other amenities on the grounds include picnic areas, open lawn, a sand volleyball pit, a walking trail, a natural area, a playground, and horseshoe pits across the street. Picnic shelters are reservable and not free. Picnic Site 1 runs 190 dollars for a half day plus a 1 dollar technology fee and a refundable 100 dollar damage deposit, capacity 120, with seven days notice required and no bounce houses or inflatables allowed. Tobacco and vaping are banned within 50 feet of the swimming beaches.

Water quality here is not covered by King County weekly swim beach bacteria sampling, so do not expect a county posting to tell you the water is clean. Monitoring is handled instead by the Steel Lake Management District, a lakefront property owner assessment district reformed in 2024 under state law for a ten year term running through 2033, overseen by a seven member advisory committee that meets quarterly at City Hall. The city publishes an annual Steel Lake water quality monitoring report, and the King County Small Lakes program tracks the lake as site 56. The lake has had incidents. In August 2015 city staff spotted a possible algae bloom on the north end and posted caution signs, though Department of Ecology testing found no detectable levels of toxins. Eurasian watermilfoil has been found and treated. In late May 2022 a raw sewage release closed the lake entirely after shoreline samples came back at 660,000 colony forming units per 100 milliliters against a 320 unit hazard threshold, and it stayed shut until June 6.

Fishing is a real part of the park, not an afterthought. The lake is stocked with rainbow trout and holds resident largemouth bass, yellow perch, brown bullhead and pumpkinseed, and it is one of only ten waters in King County carrying a seasonal fishing closure, so check current regulations before you go. There is a fishing pier on the grounds, and the adjacent Washington Department of Fish and Wildlife water access site has one concrete ramp and a small lot with one ADA stall. No restrooms at the launch, and camping is not permitted. In February 2025 the city closed on 5.5 acres of mostly wetland shoreline on the northwest side of the lake, bought for conservation rather than development, with no plans announced to build anything on it.