The best family-friendly hikes and walks in Flaming Geyser State Park

The Coal Mine Trail – Henry's Ridge & Black Diamond Natural Area offers an easy hike through a diverse landscape. You'll traverse gentle hills and established paths, winding through a mix of woodland and open spaces. The route covers 4.5 miles (7.2 km) with a minimal elevation gain of 122 feet (37 metres), making it accessible for most. Expect to spend around 1 hour and 51 minutes exploring the forested ridges and natural areas. As you hike, you might spot remnants of the area's past as coal mining lands and industrial timberland, adding a historical layer to your journey. You will encounter dense forest, marshes, and occasional views through powerline clear-cuts.

This trail is generally considered easy, suitable for various skill levels. The broader Henry's Ridge and Black Diamond Natural Area features an extensive multi-use trail network, totaling between 17 and 25 miles, accommodating hikers, trail runners, and mountain bikers. While the Coal Mine Trail itself is straightforward, some other paths in the area can include quick, alternating climbs and descents. The Black Diamond Open Space, a 1,240-acre forested expanse, is part of this region, offering a protected migratory corridor for wildlife.

The area holds significant ecological value, featuring streams, peat bogs, and wetlands that support diverse wildlife. It straddles the Cedar River and Green River watersheds, containing fish-bearing streams vital for cutthroat trout, coho, sockeye, and chinook salmon. You might even spot beavers, indicating good water quality in the area. King County Parks actively engages in forest stewardship here, including invasive weed removal, thinning, and replanting, to restore and maintain a healthy ecosystem.

The Green to Cedar Rivers Trail provides an easy hiking experience through the scenic Maple Valley region. You will find wide, well-graded paths, some with hard-packed gravel and others paved, making it a comfortable journey. As you hike, you can enjoy views of the shoreline of Lake Wilderness, and on clear days, you might even catch glimpses of Mount Rainier. This route covers 3.6 miles (5.9 km) with a minimal elevation gain of 13 feet (4 metres), typically taking about 1 hour and 30 minutes to complete.

Planning your visit to the Green to Cedar Rivers Trail is straightforward, as it is considered an easy hike suitable for various ages and abilities. The path is mostly flat and well-maintained, making it ideal for family outings or walking your dog. While generally stroller-friendly, be aware that some sections might include stairs. You can enjoy this trail year-round, as it remains snow-free even in winter.

This trail is notable for its varied and appealing scenery, passing directly through the picturesque Lake Wilderness Park. Its accessibility and gentle nature make it a popular choice for those seeking a relaxed outdoor activity. The route's design, with its mix of surfaces and consistent maintenance, ensures a pleasant experience for all who visit, highlighting the natural beauty of the area.

Embark on the Iron Brigade Loop for a moderate 5.1-mile (8.2 km) hike, featuring 307 feet (94 metres) of elevation gain and typically taking about 2 hours and 10 minutes to complete. This singletrack path winds through dense forests, offering a dynamic experience with gentle climbs and flowing descents. You will navigate over roots, rocks, and logs, encountering diverse scenery that includes marshy sections and occasional powerline clear-cuts. Keep an eye out for streams like Rock Creek and Ravensdale Creek, where the presence of beavers and freshwater mussels indicates healthy water quality within the 1,240-acre natural area.

While the Iron Brigade trail is primarily known for mountain biking, hikers generally find it accessible and enjoyable. The trail's good drainage soils and ample tree cover make it a pleasant option in various conditions. Be aware that the path can be prone to tree fall, especially after storms, so exercise caution during your visit. You have the flexibility to traverse the loop in both directions, allowing you to customize your experience.

This trail is a key segment within the Henry's Ridge & Black Diamond Natural Area, a protected natural land managed by King County Parks that was once industrial timberland. It is part of an extensive network offering nearly 20 miles of multi-use trails, connecting to other recreational areas like Black Diamond Open Space and Lake Sawyer. The trail system is actively maintained through collaboration between King County Parks and local groups, ensuring a well-kept environment for all users.