If the sign said long-haired freaky people need not apply, luckily the Sheepdogs ignored it.

Fresh off their first full-length US tour this summer, the bedraggled quartet from Saskatoon, Saskatchewan has been selling out small clubs and venues across Canada as fans flock to their modern brand of classic rock.

The band plays an old-school version of rock that often sounds like the Allman Brothers, the Guess Who and, at times, is Beatles-esque. They easily appeal to mainstream radio, but boy, do they ever jam. And for a group of guys with such an unassuming swagger and laid-back stage presence, their songs are tight. Even when guitarists Ewan Currie, also the lead singer, and Leot Hansen, veer into the realm of improvisation, their bluesy riffs maintain a structure and cohesiveness that keeps the even the rowdiest of the beer-drinking bar-crowd interested.

There is something unapologetic about the Sheepdogs – as they discuss in their new documentary – The Sheepdogs Have At It, which debuted at the Whistler Film Festival on Dec. 2 – the band was close to giving up on their dream. However, with a whirlwind couple years that began with an extremely improbable appearance on the cover of Rolling Stone (they were first unsigned band to ever make the mag’s cover), relentless touring and merciless radio play in Canada, the boys from the northern prairie are now one of the hottest bands in the country.

After a sold-out three-night run in the nation’s capital of Ottawa, Ontario, and packed houses in Montreal and Toronto in the past few weeks, it seems the Sheepdogs are ready to make the leap from dark clubs to the bright lights of stadium venues – in fact, the guys could benefit from a sounds system that is good enough to not only blast their raucous smash hits, barn-burners like “I Don’t Know,” “The Way It Is” and “How Late, How Long” but to demonstrate the nuance of their folk and blues influences in more melodic tunes like “Ewan’s Blues and Southern Dreaming” (which is pure Allmans).

As the band’s confidence grows, so too does their sound – for their latest self-titled album, produced by Pat Carney of the Black Keys, they incorporated a keyboardist, as well as some trombone into their live show.

As the Sheepdogs continue their Canadian tour, heading back west towards their familiar stomping grounds, they continue to add fans and followers – including other Canadian bands. Speaking with Jeff Innes a few weeks ago, the frontman of supporting band Yukon Blonde was effusive in his praise of the Sheepdogs and grateful for the opportunity to get to watch those guys play night in and night out.

Their lack of pretention has drawn other musicians to them and is helping to herald a new era in Canadian musical collaboration: their encores on this tour have often featured Jeff on a rousing version of The Band’s “The Night They Drove Old Dixie Down.” During a show in Toronto this past summer, they also brought Canadian indie darlings the Sadies back on stage to help out with the song. They often create one-night mini-fests with three or four bands, drawing other up-and-comers like Zeus into their nightly party. No matter who the guys play with, or how big the festival, bands and fans alike seem to gravitate towards the party they create. It’s just straight-up good times.

Clearly, this is a band on the upswing, and not a flash in the pan. As the old cliché goes, their years of toiling in obscurity have paved the way for their rapid ascension while grounding them in a firm foundation of love for their craft, an honesty and openness in their music and a natural Canadian humility.

Call them the new pied pipers of Canadian rock-and-roll – their influence is already encouraging a return to meat-and-potatoes classic rock in the face of the wompa-wompa electronic invasion. As the sold-out shows across the country (and the response in American venues from New York and Philly to the midwest have proven), there is an appetite that has yet to be sated. Keep on rockin’, boys – you’re proof that great southern-style rock doesn’t have to come from south of the Mason-Dixon.