The urban folk music boom of the 1950s and '60s left behind a seemingly endless raft of recordings by youthful solo acoustic guitar strummers, and groups learning and playing traditional music. However -- particularly from north of the Mason-Dixon line -- there aren't too many examples of bluegrass bands in this generational demographic. One simple reason for the lower profile of bluegrass in the North could be because the form itself was a relatively new one at the time, to a national audience.
Bluegrass only started to spread much beyond the Appalachian region in the '40s, after Bill Monroe's success led other groups to follow the template for his group's sound (the Blue Grass Boys also inadvertently provided a name for the genre). Also, it's worth noting that success was usually marketed as "country & western" rather than "folk," despite the genre's antecedents in much the same sort of olde European balladry as fueled all those young folkies.
There are some notable outliers, though. Probably the best example of this rare bird is The Greenbriar Boys, who left behind four full albums. Happily, they recorded for serious liner-note outfits Vanguard and Elektra, so it's easy to piece together a bit of history.
The Greenbriar Boys emerged in the late '50s from the legendary informal folk sessions in New York City's Washington Square Park/Greenwich Village scene. Mandolinist Ralph Rinzler was a serious folklorist who had been involved in planning music festivals in college, and eventually went on to work at the Smithsonian's Center for Folklife Programs -- the archives of which are now named in his honor. Banjo player Bob Yellin came from a classical background, but by the time of the group's debut had already won the legendary banjo contest at the annual Fiddler's Convention in Union Grove, North Carolina. There's even a Badger state connection; guitarist Ragged But Right!, begins to range further afield to pull bluegrass from disparate sources, with a couple original Yellin instrumentals, an obscure Marty Robbins side, and other songs learned from rare recordings or other performers.
It's the group's other pair of albums where things begin to get really interesting. Judging by the liner notes, Dian & the Greenbriar Boys must have emerged before the second Vanguard disc, as only their debut is mentioned. The album was issued by Elektra rather than Vanguard, a somewhat unusual circumstance considering the group is co-billed rather than hidden in the fine print as backup musicians. Richie Unterberger's liner notes for a 2006 CD reissue of the album mentions that Vanguard's Maynard Solomon wasn't too pleased, but let the group do the album because they really wanted to! Those notes also recount that the whole project came together extremely quickly after quick-witted producer Jim Dickson saw the group perform in Los Angeles. Dickson brought Dian James backstage, everyone hit it off, and the Boys stuck around an extra week to make an off-the cuff album. With James' husky lead voice, the quartet (aided by bassist Jimmy Bond) stomps through a set largely drawn from the repertoire of familiar names, but with a surprising blues cast to the proceedings. At the time, Elektra was gearing up for the pop success the label would experience a couple years later, and two singles were issued from the album, but it's even rarer to find those today than the album. Perhaps more surprising is that this turned out to be James' only recording.
The Greenbriar Boys would make one more album for Vanguard in the mid-'60s: Better Late than Never! For this album the group added Jim Buchanan on fiddle to broaden their sound, while Rinzler had departed for the Smithsonian. He was replaced by mandolinist Frank Wakefield, who previously played in The Kentuckians and with Jimmy Martin's band, and has since become a legend in the bluegrass field. Wakefield brought a few original songs, and co-wrote "Up to My Neck in High Muddy Waters" with Yellin and Herald. Also found here is the first released version of Mike Nesmith's "Different Drum," so I'd guess Linda Ronstadt and the Stone Poneys must have been fans of this album, as they later recorded both those songs. Better Late Than Never! is probably their best album, another step forward without leaving behind their signature sound (though nowhere near as transformative as what fellow young bluegrassers The Dillards underwent later in the decade).
And then ... the group broke up sometime before the end of the decade; I wasn't able to pinpoint an exact date by poking around online. Wakefield, Herald and Yellin all continued playing music after the band split, and Herald died in 2005. None of their Vanguard LPs have been reissued, though there are a couple of CD compilations available. I also wouldn't be surprised if they stayed in print on vinyl into the '70s, as did much of Vanguard's folk catalog. Perhaps they'll resurface sometime as part of Vanguard's Record Store Day vinyl reissues. The Elektra album apparently also remained in print until the 1970s (my copy is on the "butterfly" label), and the CD mentioned earlier was via Collector's Choice. It's also worth noting the group was part of Vanguard's New Folks anthology series, but I haven't yet tracked down a copy of that one to hear! Any and all of their releases are worth picking up by fans of bluegrass or traditional country music. (Vanguard: VRS-9104 (mono only?), 1962; VRS-9159/79159, 1964; VRS-9233/79233, 1966; Elektra: EKL-233/EKS-7233, 1963)