http://www.seatontrail.org/
I had a wonderful stroll on the trail north of Whitevale. There is parking at the Whitevale Community Centre.
There are two short sets of stairs at the start of the trail.
Also at the Community Centre are a few old buildings which are interesting. It looks like there are also some restored/repurposed buildings just east of the bridge as well. I didn't stop to check them out.
I went north, instead of south, when I noticed there was a dam on the satellite picture just off that part of trail. You can get down to the creek and walk south to get pictures of it. It also looks like there may be salmon jumping activity there. I don't see how they can get high enough to get over the dam.
Do not be tempted to follow the trail back along the creek. I did that and ran into a number of issues. Go back the way you came on the main, and maintained trail.