
The Diablo Lake Trail is an out-and-back trail with a mild elevation gain that travels through some interesting landscapes, including rainforest-like vegetation, rocky fields, a dry gorge and the Skagit River.
The trail winds alongside the Diablo Lake, a gorgeous turquoise blue body of water, for approximately four miles. The lake holds rainbow, coastal cutthroat, brook, and the federally threatened bull trout. It is a popular spot for canoeing, hiking, and kayaking. The unique turquoise hue of the lake is legendary.
The intense color is due to the surrounding glaciers which grind rocks into a fine powder which is then carried via creeks to the lake. That fine powder, known as glacier flour, is suspended in the water, giving the lake its unique color.
About The Diablo Lake Trail: Fast Facts
- Location: Ross Lake National Recreation Area
- Length: 7.51mi (AllTrails), 7.6mi (WTA)
- Elevation Change: 1538.71ft (AllTrails), 1400ft (WTA)
- Highest Point: 1950ft (per the Washington Trails Association)
- Type of Hike: Out and Back
Diablo Lake Trail History

The Diablo Lake is a man-made reservoir, created by the Diablo Dam, and is situated between the Ross Lake and the Gorge Lake. All three lakes were created by the Skagit River Hydroelectric Power Project implemented by Seattle City Light in 1917. In 1930, when the Ross Dam was completed, it was the tallest dam in the world at a height of 389 feet.
The dam generates more than 25% of the power needed for the city of Seattle. Diablo Lake is one of the most beautiful lakes in the North Cascades region offering a wide range of recreational opportunities.
The history of this region dates back over 9,000 years when indigenous people settled in the Skagit Valley. Evidence of hunting, gathering, fishing, drying of salmon, and quarrying can be found in more than 160 pre-contact archeological sites discovered in this area. These tribes have been identified as the Skagit, Swinomish, Sauk-Suiattle, and the Nlakapamuk.
The first European settlers to the area came in the mid-1800s, soon to be followed by prospectors, trappers, and homesteaders. In the 1920s, the city of Seattle targeted the Skagit River as a potential source of hydroelectric power. In the 1930s and 40s the workers on the dam lived in housing on the site of the present-day Learning Center.
J.D. Ross’ massive hydroelectric projects brought many workers and tourists to the region. To increase public awareness and generate revenue for his monumental projects. Ross set up a petting zoo, exotic gardens, and a luxury boat ride across the lake. His Newhalem cookhouse served up hearty meals for workers and visitors alike.
Although the first petition to preserve the Cascades wilderness was submitted in 1892, it wasn’t until 1968 that the North Cascades Council garnered enough public support to establish the North Cascades National Park, which opened in 1972. By 1988, 93% of the park was protected by the Stephen Mather Wilderness Protection Act.
In 1989, the North Cascades Institute proposed education as mitigation for federal relicensing of the Skagit Hydroelectric Project. In 1991 the City of Seattle partnered with the National Park Service to construct the North Cascades Environmental Learning Center.
The National Park Service donated the land for the Learning Center and the City of Seattle paid for most of the $11 million construction project. Representing the best in field-based environmental education, the Learning Center provides quality educational programs for people of all ages. Comprising 16 tree-sheltered buildings clustered on the north shore of Diablo Lake, the Learning Center offers classes, training, and education to students, visitors, graduate students, and tourists who visit the park.
Getting to The Diablo Lake Trail

Drive east on the North Cascades Highway (SR 20) to the Gorge Lake Bridge. Cross the bridge and drive another 1.5 miles, turn left onto the Diablo Dam Road. The road signage is for the North Cascades Environmental Learning Center.
Stay on the road, cross the dam, and in less than one mile you will arrive at the end of the road, the parking area, and the trailhead. There is no fee for parking. Be sure to arrive early on sunny summer days as the trail and parking lot can be quite crowded.

PARK FACILITIES AND REGULATIONS
The North Cascades National Park is proud to offer a wide range of outdoor recreational opportunities to locals and tourists as well. The wilderness of the great Northwest offers peacefulness and solitude as well as educational opportunities to learn about the amazing biodiversity of this region. This park is a source of pride and a national treasure for all to enjoy.
With this is mind, the park seeks to promote a welcoming environment for all visitors. The Park Service maintains a zero-tolerance policy toward racism or harassment of any kind. Providing a safe, enjoyable experience for all visitors is the goal of the Park Service. Any actions contrary to their goal should be reported to rangers as soon as possible.
Pets are permitted but dogs must be kept on a leash. Service animals are always welcome, of course. Developed recreation sites such as picnic areas, campgrounds, fire pits, and restroom facilities are available to all on a first-come-first-served basis. Visitors are advised to follow any rules posted at these sites. Littering is not permitted in the park. Please dispose of your trash in containers provided throughout the park or remember to carry out whatever you carried in.
No entry fee or parking pass is required to access the Diablo Pass Trail for day-use activities. If you wish to camp overnight in the park, a wilderness backcountry camping permit is required. This permit is free and can be acquired at any ranger station.
Encounters with bears are not uncommon in this area. While bear attacks are rare, there are some things you can do to remain safe while out in the wilderness. Do not allow bears to access your food. This will only cause more problems. Use containers that are bear-proof. If you encounter a bear, it is a rare treat in the National Parks, but remember this is a wild animal and as such, it can be unpredictable.
Do not run but slowly wave your arms so the bear can realize you are a human, not prey. Stay calm and pick up any small children. Move away slowly and sideways keeping your eye on the bear. If they follow, stand your ground and wave your arms again slowly. Again, do not run. A bear can run as fast as a racehorse so don’t think of it as a slow and lumbering animal.
Remember to check the current weather conditions before your arrival as road closures are common during many parts of the year. Ensure someone not with your group knows of your travel plans in case of an emergency. Cell phone service in many areas is non-existent so plan accordingly.
Navigating the Diablo Lake Trail

One-way or round-trip, the Diablo Lake Trail offers a nice hike above the shores of Lake Diablo. From June to October, Seattle City Light provides ferry service on the lake, allowing for a one-way hike and scenic boat ride back. During the rest of the year, the Diablo Lake Trail can be hiked out and back, turning around at either the Ross Dam overlook or the suspension bridge.
At about 1.5 miles in, where transmission lines cross overhead, enjoy the vista view of Diablo Lake. Walk slowly, watching your steps, and enjoy the view of cascading waterfalls into the deep gorge of over 700 feet. Continue on the trail to enjoy the cool forest and peek-a-boo views of the lake.
Just before reaching the switchbacks which lead down 600 feet to the suspension bridge at the dam, hikers cross an avalanche chute. Take care as ice often lingers here into the summer months. After crossing the chute, you reach the high point of 2000 feet elevation complete with a signed scenic overlook of the lake.
This is the turn-around spot for day hikers hiking back down the trail. If you plan to take the ferry back, or would like to see the suspension bridge, follow the switchbacks down to the bridge. After crossing the bridge, follow the trail through a tunnel, past a restroom, to the Diablo Ferry dock. The ferry only runs twice a day (9 am and 3:30 pm) during the summer months. The fare is $10. Enjoy the scenic ride back!

For more incredible hikes in North Cascades National Park, check out our guide to Finding the 10 Best Hikes in North Cascades National Park.
If you’re planning a trip to North Cascades National Park and are looking for a great place to stay, look no further than The 6 Best Hotels Near North Cascades National Park
Something for Everyone at Diablo Lake Trail
Diablo Lake is a gorgeous reservoir and the Diablo Lake Trail is a moderately easy forest day hike. Together with the Learning Center and the ferry boat ride, this is an outdoor attraction everyone is sure to enjoy. Camping overnight is available at the wilderness areas or numerous campgrounds and rentals in the area. Whether a day-hike or a longer stay, Diablo Lake is an area of interest and enjoyment for all.
Next, check out the other top hikes in North Cascades National Park outside the Diablo Lake Trail by following the links below: