I went back last weekend to finish the Seneca Greenway proper. This leaves a couple miles of Magruder Branch at the north end to complete. However, this section was much less delightful than my previous two expeditions.

Starting at Damascus Road and heading south, the first .1 was just fine - it's literally paved. Then the next mile and a half was an overgrown, downed-tree nightmare. Now, this was about two weeks after a big storm, and the trail is very near the creek, so undoubtedly some of the downed trees were new. But it looked like no regular trimming was occurring. I doused myself in DEET and wended my way slowly through downed branches.

Eventually, it opened up a bit. There definitely were some grassy spots where bug repellent is advisable, but it was clear that they were subject to regular trimming. This section was decent if unexciting, and I likely would have appreciated it more if I hadn't fought my way to it.

The trail hits Berryville Road twice, and the second one has a pretty view of the stream. The next bit was really quite nice. The trail then had a short roadwalk, but on a very quiet road. Then, it briefly was coterminous with River Road. I opted simply to cross River Road and walk to Riley's Lock on the access road, then to do a mile out-and-back on the C&O before coming back up the tail end of the Greenway. I finally did the tiny bit of River Road for completeness. It's a fast, busy road, with no sidewalk, but at least the segment required is mostly a bridge over the creek, with a sidewalk.

My initial plan was to return via Seneca Bluffs, but instead I opted after a round ten miles to get a ride back to my car.
I wouldn't recommend this section, or at least most of it, except in winter when the vegetation dies back. It's a shame, because otherwise it could make a nice loop.