Watch the Arps. with Fingerpicking: 1 online guitar lesson by TrueFire from Rhythm Guitar Greatest Hits Vol. 1
The pattern used in the song "Deep River Blues" uses two backwards rolls, adding bass strings. It uses the "E7 shape" of the three seventh chords we covered just earlier.
Pluck strings: 6 & 1 together, 2, 4 & 3 together, 1, 6, 2, 4 & 3 together. You will give the first beat of each measure a little more emphasis, creating a nice country lilt.