With their crunching guitars, ramshackle drums and vintage keyboard sounds, Portland's Blitzen Trapper have, for the past decade, put a fresh spin on '70s rock. They went back to their influences at this year's Mountain Jam, covering a pair of classics.

Above you can find their take on Led Zeppelin's 'Ramble On.' While Blitzen Trapper may take it at a slightly slower tempo, the twin-guitar attack of frontman Eric Earley and Erik Menteer does justice to the original, particularly on Earley's solo.

At the bottom of this post, they tackle Joe Walsh's 'Rocky Mountain Way.' This time it's Menteer who provides the guitar fireworks with some tasty bottleneck action, and Marty Marquis gets the clavinet setting on his keyboard just right.

Formed in Portland in 2000, Blitzen Trapper have released seven albums since 2003, with 2008's 'Furr' and 'American Goldwing' three years later being the standouts. Their most recent album was 'VII,' which was released in Sept. 2013.

Watch Blitzen Trapper Perform 'Rocky Mountain Way'