MainStage Brewing in Gunbarrel: The Story Behind the New Name

Walk into the taproom on Longbow Drive today and the room looks almost exactly as it did under its previous name. Same stainless tanks visible through the glass. Same low stage tucked against the wall. Same industrial-suite bones that have housed a brewery in this stretch of Gunbarrel since 2017. What's different is the name on the door, and even that isn't as new as it sounds.

According to Boulder Reporting Lab, the space belonged to Beyond the Mountain, a small Gunbarrel brewery that opened in 2017 and closed sometime after, without ever stating a public reason. In spring 2025, MainStage Brewing Company, the Lyons-based outfit known for its beer garden and live music schedule, took over the lease and turned it into their primary production facility and second tasting room. MainStage's beer had already been made in this building for four years before the sign changed.

The Arrangement Behind MainStage's Gunbarrel Move

The report also notes that MainStage co-founder Sam Scruby had been contracting with the Gunbarrel brewery to brew his beer there since 2021, well before any talk of a takeover. The relationship started small. Scruby described asking Beyond the Mountain's owners a simple question: whether they had room for some extra contract brewing. They did, and the arrangement held for years.

That detail adds context to MainStage's Gunbarrel opening. For most of the time MainStage has existed as a brand, the physical brewing, the tanks, the fermentation, the part of the process that actually makes the beer, was happening inside this Gunbarrel building. The Lyons taproom sold it. Longbow Drive made it.

Scruby has an Upslope Brewing background, five Great American Beer Festival medals, and a World Beer Cup award behind him, which is part of why the contract-brewing relationship worked in the first place. Co-founder Eric Kean spent his career in brewery events management at Left Hand Brewing and at Planet Bluegrass, and ran the Left Hand Brewing Foundation before helping start the Colorado Strong Fund with the Colorado Brewers Guild during the pandemic. Between the two of them, Gunbarrel wasn't a stretch. It was a room they already knew.

What Actually Changed on Longbow Drive

The formal takeover means a few real differences for anyone who used to stop in for a Beyond the Mountain pint. MainStage's liquor license covers wine and canned cocktails alongside beer, which Scruby has said matters for people who show up with someone who isn't a beer drinker. The tap list is now entirely MainStage's own, brewed on site rather than shared with a departed tenant's recipes.

The calendar is where the shift shows up most. MainStage runs a Friday night bluegrass series called MainGrass, live music on Saturdays, a Wednesday bluegrass pick, and rotating trivia and karaoke nights, carrying over the same live-music identity that made their Lyons location a gathering spot. Scruby has said he sees live music as underserved in Boulder generally and plans to lean into it further, especially through the winter months.

One thing hasn't transferred over. The Gunbarrel location is set up for light snacks rather than a full menu. If you want the pizzas and sandwiches MainStage is known for, that's still a Lyons-only offering for now. It's worth knowing before you plan a dinner stop rather than a drink stop.

A Brewery Space With a History

Scruby has pointed out that Beyond the Mountain wasn't the only small brewery to close in Gunbarrel in recent years.

MainStage's move gives the former brewery a new chapter. Scruby said he's glad the takeover means the space stays alive rather than going dark or turning into something with no connection to what came before.

Gunbarrel's business district doesn't have the density of Boulder proper or the walkable strip Niwot's Second Avenue has built, so Twin Lakes offers a different kind of place to spend an evening.

The Walk That Doesn't Care Who's Behind the Taps

None of this touches the other fixture of a Gunbarrel evening, which sits just down the road and has outlasted every business that's ever poured a beer near it. Twin Lakes Open Space is the pair of small reservoirs that the Boulder and Left Hand Ditch Company has operated since 1910, originally built to store water for agriculture. Boulder County now owns the surrounding land, and the dirt path that rings both lakes has become the closest thing Gunbarrel has to a shared backyard.

The two lakes aren't identical in character. The east side keeps dogs on leash and has a small beach area to sit near. The west side is off-leash. A wooden footbridge connects the two, and the loop is short enough, under two miles, to work as a before-dinner walk rather than a weekend expedition. There are no restrooms or picnic tables out there, so it stays a walk-through rather than a destination to camp at, which is part of what keeps it uncrowded.

The neighborhood itself grew up around these two lakes in the 1960s, when the nearby IBM plant needed housing for the executives and employees it was bringing to Boulder County. Homes were built close to the water, and the lakes have stayed the center of gravity ever since, long after IBM's role in the area faded. Watch the sunset from the west bank and the Flatirons show up almost on cue, and the coyotes start up not long after, which regulars mention often enough that it's become part of the loop's reputation rather than a surprise.

Put the two pieces together and you get the actual shape of a Gunbarrel evening that hasn't needed a name change to keep working. Walk the lake loop while there's still light, then land on Longbow Drive for the Wednesday pick or a Friday night of MainGrass. The brewery's name changed in 2025. The walk that ends there hasn't changed in longer than anyone currently living in Gunbarrel has been around to notice.

If you're the kind of neighbor who already has an opinion about which side of Twin Lakes is better at sunset, or which night at the new taproom is worth showing up for, I'd like to hear it. I've spent more than 30 years getting to know these Boulder County corners the slow way, one neighborhood at a time, and Gunbarrel's small shifts are the kind of thing I pay attention to even when nobody's buying or selling anything. If you want to talk shop about the neighborhood, or anything else Boulder County, Kristi Clary would love to connect.

This article is general information, not legal, tax or financial advice. Consult a qualified professional about your situation.