A good little base camp for the northern portion of the Redwood National Park. However, internet is non-existent here so plan accordingly. We stayed at the Mill Creek campground for a single night during our trip through the Redwood National Park. The national park is a strange one since several state park existed before and the national park encompasses all of them. You won't find a specific national park campground here. The various state parks in the area are based on various old growth redwood groves. You will see lots of very tall trees throughout the area.
There's a steep road into the campground and it's a bit curvy so bigger rigs may not be able to get in. The dump station and water is down the hill between the two campground loops. There's no internet here so you'll need to download park information beforehand if you are planning things in the evening. There's also not much to do inside this park other than a few short trails. We just used this as an overnight stop when visiting the parks.
The campsites are decently spread out and fairly level, though it varied a bit from site to site. The sites are definitely no-frills, but you have a nice wooded, quiet site for the night. This campground was definite on the quiet side and there's no road noise.
The bathrooms and showers were generally clean but the fixtures and building are pretty dated. The dump station was adequate and there was fresh water fills available.
There's just one short trail available from the campground and we ended up just talking a walk through the campground. There are plenty of trails and sights in the surrounding area.
This park is in the northern section of the Redwood National Park and there are numerous trails and redwood groves to visit. There are visitor centers scattered through the national park as well. This is a good place to pick up a map. Make sure to use Google Maps for points of interest and AllTrails to find interesting hikes.