You're talking about the "Skyline to Sea" trail. (Or the way you're talking about it, it's more like "Sea to Skyline" trail.) That is a beautiful hike, but people should be warned, it's a 10 mile uphill trek. If you're healthy, it is a beautiful hike. I'm old, so it takes me most of the day to make that trek.
The first part is pretty flat, but 5 miles in there is some real steep climbs (>15%). The total length is almost a marathon, if we're talking about the same route.
