I have seen these folks and they are the real thing!
From their site:
Red Diesel plays country, bluegrass, and Americana covering popular songs, catchy originals, three-part harmony and good pickin'!
Hailing from Sweet Home, Bend and Lebanon, band members are Betsy Yochelson (stand-up bass, vocals, songwriter), Theron Yochelson (mandolin, vocals, songwriter), Mark Barringer (guitar, vocals, songwriter) and Steve Speth (banjo, Dobro). Betsy & Theron have played together for 24 years. Red Diesel formed in Jan 2013 and has taken off naturally drivin' the bluegrass, revved-up acoustic country,