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About · Est. 2017 · Boulder, Colorado

A Boulder workshop that paints flags, ships gear, and has DNF'd so you don't have to.

Tiny balls. Big mountain energy. Eleven craftspeople, three athlete ambassadors, and one stubborn belief that trail markers should be built by people who have actually carried them past mile 78.

By the numbers · 2017 to present
2017Founded in Boulder, CO by Jess & Marco
11Full-time craftspeople & designers
41Countries shipped since 2017
612Documented ultramarathon finishes carried
11,400+Flags replaced under our lifetime guarantee
84,300Orders fulfilled in 2024 · 99.2% on-time
6.8 gAvg. weight across the core flag line
2017Founded in Boulder, CO by Jess & Marco
11Full-time craftspeople & designers
41Countries shipped since 2017
612Documented ultramarathon finishes carried
11,400+Flags replaced under our lifetime guarantee
84,300Orders fulfilled in 2024 · 99.2% on-time
6.8 gAvg. weight across the core flag line

Independent, founder-owned since 2017. No VC, no algorithm chasing, no Amazon storefront.

The Origin · Leadville, Colorado · August 2016

A blown marker tape at mile 78 became a product line.

Weaselballs started as a mistake.

In August 2016, Jess Halverson was crewing her sister at the Leadville Trail 100. Marco Reid was pacing a friend through the Hope Pass out-and-back. Somewhere around mile 78, in the dark, between the Sugar Loaf aid station and the May Queen cutoff, a stretch of course tape came loose from its stake, swung across the trail, and sent two runners — including Marco's — off-route for nineteen minutes. Nobody DNF'd that night. But Jess and Marco spent the next six weeks arguing about how something so small could cost so much in a 100-mile race, and by November they'd rented a 480-square-foot room above a bike shop on Broadway and started painting reflective flags by hand.

The first run of 200 Weaselballs sold out in nine days. The replacement program — the one that now sits at 11,400+ flags honored — launched the same month, because the first 200 weren't quite right and we knew it. Seven years later the workshop is at Suite 3B, 2410 Broadway, with eleven full-time craftspeople, and the room above the bike shop still has the original paint-splattered floorboards.

We have DNF'd. We have been the runner who came in at 29:59 and the pacer who missed a turn in the dark. Every product in this catalog was built for the version of the sport where those mistakes happen — and the people who refuse to let them end a race.

The original Weaselballs workshop above the bike shop on Broadway, paint-splattered floorboards still visible
The original 480 sq ft room, November 2016. The floorboards are still there.
Jess Halverson, co-founder and workshop director, in the doorway at Suite 3B Marco Reid, co-founder and head of design, holding a hand-painted trail flag
The Founders

Two people. 142 finishers between them. One stubborn workshop.

Weaselballs is run by two named humans who have paced, crewed, and DNF'd at the distance. Not a design studio. Not a licensing deal. Two people in Boulder.

Jess Halverson

Co-founder · Workshop Director · Former Leadville 100 crew chief

Jess ran her first 50K in 2009 on a borrowed pair of shoes and has crewed at fourteen Leadville 100s since. She runs the Boulder workshop floor — paint schedules, fulfillment, the lifetime replacement program, and the very specific argument with our shipping partner about box corners. She has paced four 100-mile finishes and crewed eleven more. Her favorite flag in the current line is the slate-grey Bombshell.

  • 14 × Leadville 100 crew chief
  • 4 × 100-mile pace finishes
  • Owner of one extremely opinionated shop dog, Pinto

Marco Reid

Co-founder · Head of Design · Pro pacer

Marco has paced at Western States, UTMB, and Hardrock a combined thirty-one times — twenty-two of those with runners who went on to finish. He designs every flag in the line and hand-paints the prototypes himself, usually between 11pm and 3am after his daughter is asleep. He is the reason the Weaselball weighs 4.2 g and not 5.8 g, and the reason it shows up at 1.6 km on a headlamp instead of 1.1.

  • 31 × pace finishes at 100-mile races
  • 3 × UTMB top-10 pacing credit (since 2020)
  • Has personally replaced 1,400+ flags under the lifetime program
The Workshop · Suite 3B, Boulder

Eleven people. Three roles. One paint-splattered floor.

Small enough that every flag passes through at least two sets of hands. Big enough to ship 84,300 orders in a year without missing a Tuesday.

  • 7

    Hand-painters

    All former ultrarathon pacers with a combined 142 finishers across UTMB, Hardrock, and Western States. Each flag is painted on bamboo, sealed, and signed.

  • 2

    Gear designers

    Marco plus one. They prototype every new marker, reflective panel, and race-bib clip on a single sewing machine that has been repaired four times.

  • 1

    Fulfillment lead

    Owns the 72-hour shipping promise, the lifetime replacement inbox, and the ongoing argument with EcoTranz about pallet wrapping.

  • 1

    Workshop dog

    Pinto. He has never paced a 100-miler but has finished every single one of our morning standups and once ate a prototype.

Plus three athlete ambassadors, twenty-two race-director accounts on file, and a rotating cast of pacers who drop by the workshop on rest weeks.

Ambassadors & Standards

The runners who carry the flags. The standards we hold ourselves to.

Three officially listed athlete ambassadors. Two third-party certifications. One percent of every order, every month, no exceptions.

Ambassador · 100-mile

Anaïs Kovacs

Three-time top-10 at UTMB. Has carried Weaselballs flags on every flagged section of the course since 2021 and consulted on the slate-grey Bombshell colorway.

Read her Chamonix race report
Ambassador · 100K–100M

Daniel Mwangi

Two-time Western States finisher and creator of the Mogollon Monster 240 course. Helped spec the high-visibility orange we now ship as standard on every flag set.

See the course-marking case study
Ambassador · 50K–100K

Priya Vasquez

Cuyamaca 100K course co-founder. Carries our 4.2 g Weaselball on every flagged turn and runs the custom course-marking program for the Western US.

Custom marking program
Certification · Climate

Certified Climate Neutral since 2023

Verified by Climate Neutral. Every order ships carbon-neutral via our partnership with EcoTranz. We measure, reduce, and offset — and publish the numbers annually.

View our Climate Neutral profile
Commitment · 1% for the Planet

1% of every order to the Access Fund

Since 2019 we have donated 1% of every order to the Access Fund through 1% for the Planet — funding climbing access, trail stewardship, and the public lands our sport runs on.

See our 1% for the Planet listing
Recognition · 2024

Best Small Outdoor Brand 2024

Awarded by the Independent Outdoor Retailer Association. Featured in Trail Runner Magazine, Outside, Ultrarunning Magazine, and Podium Runner between 2020 and 2025.

Press & field journal