Campsites at Colonial Creek South Campground (2026 Guide)

For more, see Campsites at Gorge Lake Campground (2026 Guide).

For more, see Campsites at Lakeview Campground (2026 Guide) and Campsites at Lower Goodell Group Campground (2026 Guide).

For more, see Campsites at Harlequin Campground (2026 Guide).

For more, see Newhalem Creek Campground at Newhalem Creek Campground North Cascades National Park (2026 Guide).

For more, see Best of North Cascades National Park: Best Month to Visit (2026) and North Cascades National Park Weather: Best Season to Visit (2026 Guide).

For more, see complete visitor guide, all campgrounds, hiking trails, lodging and accommodations, Goodell Creek Campground at Goodell Creek Campground North, and Purple Point Campground at Purple Point Campground North.

What Makes This Campground Different

Most campgrounds in North Cascades National Park Complex sit along the same stretch of highway, but colonial creek south campground has a few specific traits that set it apart. It is the primary access point for Diablo Lake's south shore, which means you get a fully accessible fishing pier and a boat launch right at the campground. The boat launch has a problem worth noting - the Diablo Lake boat launch at Colonial Creek South is not usable for launching most powerboats due to silt accumulation. Expect shallow or no water at the ramp. You may need to carry your boat to or from the water.

The campground sits in old growth forest, which means real shade in summer and damp conditions in spring and fall. The ten winter sites (64-73) are walk-in and tent-only, which keeps the RVs and trailers out of that section entirely. During winter, there is no potable water, no trash service, and no fee. Vault toilets remain available. Snow may be on the ground, and sites can be difficult to access.

Site Selection Strategy

The campground has 93 total sites, with 19 designated as tent-only. The walk-in sites 64-73 are the ones that stay open through winter. The remaining sites are reservable during peak season. If you are booking for summer, the reservation window opens six months in advance at Recreation.gov, and you can also book as little as seven days ahead. Check-out is noon.

Rangers will tell you that sites closest to the water fill first, and for good reason. The lake access and the fishing pier are the main draws here. The Thunder Creek and Thunder Knob trailheads are also accessible from the campground, which means you can hike without moving your vehicle. Given the break-in warnings along SR 20 - smash-and-grab theft is not uncommon at trailheads - leaving your car at your campsite instead of at a trailhead parking lot is a genuine advantage.

Seasonal Operations and Fees

The fee structure at colonial creek south campground changes three times a year. Understanding which period applies to your visit saves confusion at the pay station.

Summer Reservation Season (Late May to Mid-September)

• Fee: $24 per site per night
• Reservation required: Yes, through Recreation.gov or by phone at (877) 444-6777
• Occupancy limits: 2 vehicles, 8 people, 3 tents per site
• Check-out: 12:00 PM

This is the only period when the full campground is open. Water and trash services are provided. The boat launch, fishing pier, and trailheads are all operating at full capacity, minus the silt issue at the boat ramp.

Fall First-Come, First-Served (Early September through October)

• Fee: $24 per site per night
• Payment: Through pay.gov at tinyurl.com/NOCACamping
• Services: Potable water and trash services still provided

This period starts once reservations end in early September and continues through October. Same fee, same services, but you cannot reserve. Show up and claim an open site. Weekdays are generally easier than weekends.

Winter Season (October to Late May)

• Fee: $0
• Sites available: 64-73 only (walk-in, tent-only)
• Services: None. No water. No trash pickup.
• Toilets: Vault toilets available
• Snow: Possible on ground. Sites may be difficult to access.

Ten sites, no fee, no services, no reservations. You carry in everything you need and carry out all your trash. This is bare-bones camping for people who know what they are doing. The research data indicates the winter season runs October to late May, and per the NPS hours data, the winter exception runs from September 15 through May 20. The exact transition dates vary slightly by year, so check the official website for current dates.

Current Conditions and Alerts (May 2026)

The research data includes nine active alerts for North Cascades National Park Complex. Several directly affect colonial creek south campground.

SR 20 Closure at Milepost 130

State Route 20 is closed at milepost 130 - that is the Colonial Creek Campground location - in both lanes. The Diablo Lake Overlook is not accessible beyond the closure. This is the most consequential alert for anyone planning to visit. The WSDOT real-time map is the best source for updates. If you are approaching from the west, you may not be able to reach the campground at all. If you are already in the area, confirm the road status before departing.

Boat Launch Silt Accumulation

The Diablo Lake boat launch at Colonial Creek South is not usable for most powerboats. Silt has filled in the launch area. You may find shallow or no water at the ramp. Expect to carry your boat to or from the water if you plan to launch anything. This is not a temporary repair situation - it has been an ongoing condition.

Break-in Warning Along SR 20

Break-ins are not uncommon at trailheads along State Route 20. Remove valuables and electronics from your vehicle, and take any associated charging cords. Smashed windows are the typical result of leaving items visible. The campground itself is generally safer than the trailhead parking lots, but do not assume your car is immune anywhere along this corridor.

Flooding and Landslide Damage

The park complex experienced severe weather events following flood damage in December 2025. Unsafe conditions persist in some areas, and basic infrastructure is limited. Stehekin, in particular, is prone to flash floods and debris flows, especially in post-fire terrain. Colonial Creek South itself is not in the Stehekin area, but the broader park conditions mean that services and road access may be unpredictable.

Hiking and Recreation

Two primary trails are accessible from the campground.

Thunder Creek Trail follows Thunder Creek through old growth forest. It is a longer, flatter route suitable for day hikes or overnight backpacking if you connect to the backcountry. The trail register at the trailhead will give you current conditions.

Thunder Knob Trail is a shorter, steeper option that climbs to a viewpoint overlooking Diablo Lake. Early morning is your best bet for clear views before afternoon clouds build in. The elevation gain is worth it - from the top you can see the full expanse of Diablo Lake and the surrounding peaks.

The accessible fishing pier is a notable feature. It provides lake access for anglers and visitors with mobility limitations. The pier is on Diablo Lake, and the fishing is typical for North Cascades waters - think trout and kokanee.

Practical Takeaways

1. Check SR 20 status before driving. The closure at milepost 130 may prevent access entirely. Use the WSDOT real-time map.
2. Book summer reservations at Recreation.gov. Six months in advance for peak dates. $24 per night. Reservation required late May through September.
3. Winter camping at sites 64-73 is free but spartan. No water. No trash service. Vault toilets only. Pack out everything.
4. The boat launch is unreliable for powerboats. Silt accumulation means you may need to carry your boat. Canoes and kayaks are more manageable.
5. Do not leave valuables in your vehicle at trailheads. Break-ins are common along SR 20. Take everything with you.
6. Fall camping (September to October) is first-come, first-served. Same $24 fee, but no reservation. Pay through pay.gov.
7. Cell service drops out along much of SR 20 through this area. Download maps and reservation confirmations before you lose signal.

Final Thoughts

Colonial Creek South Campground offers something unusual in the national park system: a genuine seasonal transition from full-service reservation camping to free winter walk-in sites. That flexibility is rare and worth using if your schedule allows shoulder-season visits. The catch, as of 2026, is the road closure and the broader flood-related infrastructure issues affecting the park complex. Anyone who has driven SR 20 in the spring knows that road conditions change fast. The common mistake - and almost everyone makes it - is assuming the highway will be open because it is May. Check first. The campground will be there waiting when the road is open, and the fishing pier and trails make it one of the more complete basecamp options in this part of the North Cascades. For a full breakdown of all campgrounds in the area, check the all campgrounds page.