:::The Bull Run River article is shorter at the moment but sourced and not copied directly from sources. The watershed article, alas, is only partly sourced, and the last paragraph of the "Geology and geography" section has been copied verbatim from the Portland Water Bureau page here. Noticing this one example of copying makes me think there might be more, but it's a big job to re-research everything to see what extent that might be true. Rather than merging, I'd like to see the watershed article brought into compliance with WP:V, the Manual of Style, and WP:COPYVIO while the river article expands slowly and separately following the encyclopedia's guidelines. I added some material about whitewater sports to the river article this morning, and I'll try to help with the watershed article as well, as time allows.