Yes, I think it's open-G tuning, though her banjo is tuned up to G#. You can match this with a capo on the 1st fret. Here's some tab I wrote several years ago for this tune. A bit simpler than Kendl's but it may be helpful.
Beautiful tune. One that always seems to cry out to be played a little slower than the tempo fiddlers often kick it off. As Carl said it's a tune that lends itself to sorrowful and wistful in whatever amount fits with how you feel on any particular day. Here is Ernie Carpenter playing Elk River Blues.
Find a fiddle player that can slow this tune down and it's a lovely tune to play in duet.
Thanks, Carl. That's the first time I've seen the new Fiddlers Companion site. the larger print does make it easier to read, so I'll have to explore it some more, even if I am a grumpy old curmudgeon who likes the old site, since that's the first place I found the tunes.