Cape Flattery is the northwestern most point in the lower 48. It is accessed by a 3/4 mile trail (which is not stroller friendly) which leads visitors to the edge of the cape and a viewing platform with incredible vistas.
Parking is free. There is a pit toilet in the parking lot.
The hike to the edge of Cape Flattery is a very scenic hike suitable for all ages. I took my senior aunt and 4 year old twins on this hike which everyone enjoyed and nobody had issues with. There is a decline at the beginning of the trail (which does mean you have to come back up) but the incline was not very bad and my Aunt reported that is was much easier than she thought it would be. The trail heads through damp forest on a wide trail for about 1/3 of a mile before you reach a series of cedar boardwalks which traverse wetlands and protect the flora. This is where a stroller would be impossible to use. I saw one family ditch their stroller on the side of the trail so they could continue. My advice is to use a child carrier for infants and new walkers. Otherwise, I would say any child over the age of 2 1/2 should be able to walk this trail with no issue.
After about 3/4 of a mile on the trail, a glimpse of the water will be seen and a very short side trail veers to the left. take the trail and be taken aback by the views. There are no words that truly describe the beauty of this spot. Actually, I suggest taking any advantage of every viewpoint because they all offer something unique.
At the end of the trail you will come to a viewing platform which is accessed by a a short ladder (about 3 or 4 steps). I saw people of all ages (and even a dog) get up and down the platform with no issue. The views are sweeping and wildlife is frequently spotted. Evidently we missed a passing grey whale by about 5 minutes, but we did get to see a bald eagle and a couple puffins. Sea otters, seals, orcas, and humpbacks are seen off the cape as well.
Total time at the cape was less than 2 hours for us. People with older children can walk the trail out to the cape in about 20-30 minutes but those of us with young children need to give themselves about 40 minutes. We only stay at the end of the cape for 15 minutes due to antsy children but I could have easily spent an hour watching the waters and taking in the views.