At some point during the week we were there we stopped for a quick look (in the rain, as usual) at Devon Falls, a very easy walk of 50 yards from the end of Harvest Drive. It was a beautiful little waterfall.
The interpretive plaque on the viewing deck described the rare Maidenhair Fern, growing directly of the rock here, in the moist mist of the waterfall. That's it, in the lower corner of the photo, right on the cliff. It grows in a fan shape, unlike the usual fern shape, and we have plenty of it in deciduous woods here in the valley. It's a very pretty waterfall.
It's also an Earthcache, a geocache with no hidden box to find, but some questions to answer about the geology of the site. This is a good example of a cascading waterfall, formed by a harder higher layer, with undercutting of the softer sandstone below, so the water can fall freely all the way down. I've submitted my answers!
If you're in the area, you can find Devon Falls if you turn off Whatcom Road onto Westview Blvd., and almost immediately onto Harvest Drive. Park at the end and follow the trail downhill.