Since 93% of North Cascades National Park is designated as a wilderness area the only way to see most of the park is via trails into the interior. There are several shorter trails accessible from Washington Highway 20. These will at least introduce you to some aspects of the park and are well worth taking.
Gorge Creek runs South from the high mountains into the Skagit River. The rock around the creek is very hard forming a canyon that is very deep and very narrow in some places. In other places the creek is near ground level. Note the flood damage in Photos 2 and 3.
Some places in the park, like this cut along the highway, provide a fascinating glimpse into the geological past of the North Cascades. The rock you see here is predominately Orthogneiss Bedrock (the dark grey). 100 million years ago this rock was 15 miles below the earth's surface. Some 40 million years ago this rock was invaded by veins of quartz and feldspar (the lighter bands). The reddish deposits are Iron Oxide. These rocks were pushed up from below the surface to create the North Cascades.
Many years ago glaciers carved the strong metamorphic rock composing the top of Colonial Peak. Although the glaciers continue to grind away the tough rock of Colonial Peak defies much change. Colonial Peak is typical of the mountains forming the North Cascade Mountain Chain.
East of the dam Diablo Lake is formed by the water held back by the dam. Boating is very popular on Diablo Lake and the scenery is spectacular. The interesting and intense blue-green color of Diablo Lake is formed by something called "rock flour". "Rock flour" is formed by the glaciers in the nearby high country grinding rock against rock to produce a fine silt that meltwater streams carry into the lake below. The "rock flour" then reacts with light to reflect this beautiful color.
Along the sides of Diablo Lake, near the entrance of larger streams to the lake you will see large log booms set up. These booms stop debris from entering the lake. This debris could endanger boaters and damage the dam intake and generator impellers.
Diablo Dam is one of three dams along the portion of the Skagit River located inside the park. It is the easiest one to access by car, since you can drive across it and park on the other side. I found it very interesting and the views were great. make sure you stop at the Diablo Lake Overlook east of the dam and take the short interpretive trail. These are some of the best views along Washington Highway 20.
If you are entering from the west, begin your tour at the North Cascades National Park Visitors Center. Here you can get a brochure and newspaper for the park; look over maps; and get recommendations from the helpful rangers on how to best enjoy your visit based on your interests and the amount of time you have to visit. Unfortunately, I entered from the east so I drove through most of the North Cascade Highway before I got to the visitors center.
When driving along the North Cascades Hwy you will notice that there are a lot of large lakes. Most of these along the roadside were created by damming the Skagit River. First is the Baker river system.
North of the town of Concrete are two large lakes Lake Shannon and Baker Lake. Both are held back by large dams. After that you will find 3 dams on the Skagit River that you follow on the hwy. Gorge Dam is the first of these followed by Diablo Dam and finally the largest of the bunch, Ross Dam.
Some of these depression era relics are not very accessible and only obscured glimpses are given along the drive. Others are very easy to get up close to and see the massive structures it takes to hold back that much water.
Clearly marked and almost impossible to miss, these falls are right along the highway about halfway between Newhalem and Diablo. You go over a large bridge that crosses the falls - on the western side of the bridge there is a pretty good sized parking lot. From here, you can hike to an overlook of Gorge Dam, or you can cross the highway for a closer look at the falls, which are just under 250 feet tall.
Please see my North Cascades travelogue for some other waterfalls seen from the highway.
Route 20 is the scenic drive that cuts through the park. There are plenty of overlooks and turnouts as you head through the park, including several impressive lake views. For the most part, the road is pretty straight and gradually rises through the mountain range. Take your time as you drive the highway and get out when possible to take in the views.
Please see my North Cascades travelogue for some scenes from the highway.
Also in the Newhalem area - another quick little trail from a parking lot across the creek near the power plant. The grounds are neatly landscaped and lead to this pretty little waterfall. There are times that the foliage and waterfall are lit up, but they were reconstructing some of these features in 2007, so there was no light show. If you enjoy waterfalls, this is easily found and easy to get to.
This is the one trail I was able to squeeze in - it's a very easy, flat, and short (1/2 mile) trail through an old growth forest of, you guessed it, Cedars. It also passes along Newhalem creek - the start of the trail is a short bridge over the water. The most challenging thing about this trail is finding where to park. Since it was later in the day, I just parked along the road near the entrance - I'm not sure if you can park there during the day when folks are working. It's a very serene trail, and worth your few minutes, especially to marvel at the trees, which are centuries old.
Ladder Creek Falls only drops about 100 feet (30 m) which by the comparison of the other falls in the area isn't a very large drop. It does however make up for it with its accessability and scenic setting.
The falls are surronded by a very green moss covered canyon and is located in a fairly dense forest which prevents light from coming through the trees.
The falls are also lighted in the evening or at least claim to be. The area was used to show off the beauty of the area while the dam was being introduced to the public and their acessability has remained quite easy.
Ketchum Creek Falls descend about 200 feet (60 m) in a staggering rock hopping path. It is a very graceful waterfall but does not see much attention.
Nearby Gorge Creek Falls steals most of the attention since it is labeled on park maps and also has many road signs directing visitors to take a look.
Ketchum Creek Falls is actually the more visually appealing waterfall. It can be seen from the road and the most common picture taking location is actually from the road.