Saltwater State Park stands as a defining natural and recreational landmark for Federal Way, offering unparalleled public access to the Puget Sound shoreline and its vibrant marine environment. It holds the distinct designation as the only state park in Washington to feature a dedicated underwater diving park, complementing its popular beach access, well-maintained picnic facilities, and extensive network of walking trails. For the residents of Federal Way, this park serves as a vital artery to the region's natural splendor, providing a diverse array of outdoor activities that are a treasured part of community life and otherwise rare within city limits. Its continued existence ensures a precious segment of the Sound's edge remains publicly accessible, a valuable contrast to the predominantly privately held waterfront along this stretch.

The establishment of Saltwater State Park is rooted in a forward-thinking commitment to public land preservation that began in the early part of the 20th century. The land for the park was initially acquired in the 1920s, a period marked by growing recognition among local communities of the critical need to secure waterfront access for present and future generations. It was formally designated as a state park with the clear intent of creating a popular public beach and an area for camping, catering to the recreational demands of the then-rapidly expanding south King County region. Over the decades, the park has undergone significant evolution, seeing the addition of more structured recreational amenities and, most notably, the innovative development of its unique underwater park. This specialized marine component was carefully constructed through the strategic placement of various concrete structures, including salvaged sections of the old Alki Point streetcar line and other robust materials, to form artificial reefs. These structures were specifically designed to attract and support diverse marine life, thereby significantly enhancing opportunities for scuba diving and underwater exploration. This imaginative approach transformed what might have been a simple beach into a vibrant ecological and recreational hub, setting it apart from other waterfront parks in the area.

Today, Saltwater State Park offers a rich and varied landscape for all who visit. The shoreline itself is a dynamic blend of sandy and pebbly beach areas, providing an inviting space for leisurely walks, sunbathing, or engaging in the timeless pleasure of building sandcastles during low tide. The renowned underwater diving park, easily accessible from the main beach, comprises a series of carefully placed artificial reefs and structures that now serve as a thriving habitat for a wide array of Puget Sound marine creatures, making it a highly favored destination for divers of varying experience levels. Moving inland, the park transitions into a lush, mature second-growth forest, through which numerous well-maintained walking trails gently wind, offering shaded paths, tranquil natural environments, and intermittent scenic glimpses of the Sound. Throughout the park, numerous picnic areas, complete with tables and grills—some thoughtfully placed under covered shelters—are scattered, providing ideal settings for family gatherings, community events, and peaceful outdoor meals. Modern restroom facilities are conveniently located near the primary parking areas and the main beach. Adding to its natural charm, McSorley Creek flows gracefully through the park, ultimately emptying into the Sound, contributing to the area's ecological diversity and serving as a crucial salmon spawning stream during relevant seasons.

The park experiences active use throughout the year, with peak visitation naturally occurring during the warmer months. The beach remains a consistently popular destination for swimming, wading, and beachcombing, particularly for families seeking respite and recreation. Enthusiasts of kayaking and paddleboarding frequently launch their craft from the shore, eager to explore the often-calm waters of the Sound. The network of trails draws a steady stream of walkers, joggers, and general nature enthusiasts, all seeking both physical exercise and a profound connection with the natural world, with ample opportunities for birdwatching among the dense tree canopy and along the water's edge. Scuba diving, however, stands out as a preeminent activity, drawing divers from across the broader region who come to explore the intricate underwater environment and its diverse marine inhabitants, which commonly include various species of crabs, colorful sea stars, numerous fish, and even occasional sightings of octopus. Picnicking and barbecuing continue to be cherished traditions, with many groups choosing to reserve shelters for larger, more organized gatherings. Beyond recreation, the park also occasionally hosts educational programs and environmental stewardship activities, effectively utilizing its rich natural setting as a living classroom.

Before embarking on a visit to Saltwater State Park, there are several important considerations to keep in mind to ensure a smooth and enjoyable experience. As a Washington State Park, vehicle access necessitates a Discover Pass, which can be acquired either on-site at the park or through advance purchase. While the beach undeniably offers inviting opportunities for water activities, it is crucial to remember that the Puget Sound water consistently remains quite cold, even during the height of summer, and caution is always advised for swimmers due to potential currents. Tidal fluctuations significantly alter the available beach area, with low tide revealing substantially more shoreline for exploration and discovery. For individuals keen on exploring the underwater park, it is imperative to possess personal diving equipment and appropriate training; the park itself does not provide rental gear or instructors. Visitors are strongly encouraged to uphold the park's natural integrity by staying on clearly marked trails, refraining from disturbing marine life or plant ecosystems, and diligently disposing of all waste in designated receptacles, adhering to a "leave no trace" philosophy. Leash laws are strictly enforced for all pets within the park's boundaries. Given the park's considerable popularity, especially on sunny weekends and holidays, parking lots can frequently reach capacity, making an earlier arrival in the day often advisable for securing a spot. Despite its location within Federal Way, visitors should be aware that cell phone reception can be intermittent in certain areas of the park, primarily due to the natural terrain and dense tree cover.