The World’s Tallest Glass Tree Festival Returns to Yerkes Observatory With a Ruby-Red Glow and Expanded Recycling Mission

December 5-7 and 12-14, 2025 at Yerkes Observatory

LAKE GENEVA, WI – The World’s Tallest Glass Tree Festival is back and bigger than ever at Yerkes Observatory, inviting visitors to help create a 36-foot glass tree that glows bright red against the winter sky. For the first time, every festival ticket includes access inside Yerkes’ awe-inspiring interior, where guests can stand in the big dome beneath the world’s largest refracting telescope.

The event runs December 5–7 and December 12–14, transforming the Observatory grounds into a holiday village filled with live music, firelight, art, and family activities. Tens of thousands of visitors from Wisconsin, Illinois, and beyond are expected to take part in the live creation of the world’s tallest glass sculpture built from molten, recycled glass.

Build the Tree Yourself

Each evening, glass artist Jason Mack and his team will invite visitors to take a gathering iron tipped with 2,000-degree molten glass and drizzle it onto a spinning steel frame, helping build a glowing monument of color and collaboration.

“This festival is about more than a spectacle,” said Producer Rob Elliott. “It’s about giving people a hands-on way to experience art, community, and sustainability all in one place. When families help add glass to the tree, they’re literally shaping something that represents imagination and togetherness. It’s a really fun experience.”

What to Expect

• Live music nightly from 4–7 p.m.
• A heated Winter Market Tent featuring regional artisans, gift shops, and a bar for beer and wine
• Chainsaw sculptors, outdoor fire pits, and lounge seating for cozy gatherings
• A warming tent with kids’ activities each day provided by the Williams Bay Recreation Department
• Local favorites such as Magpie’s Den & Pen food truck, along with coffee and hot chocolate huts
• Glass art demonstrations, workshops, and interactive experiences

The festival concludes Sunday, December 14 at 7 p.m., with a joyful Star Topping Celebration that begins at 4 p.m when a hand-blown glass star is placed atop the tree. Guest are encouraged to arrive early for the best experience.

Glass Recycling Program Expands

This year, the festival expands its environmental mission through a new partnership with Don’t Trash Glass, a national program from the Glass Packaging Institute. The initiative brings new glass recycling services to Wisconsin and Illinois restaurants and bars, collecting and redirecting thousands of bottles back into the manufacturing stream instead of landfills.

Glass can take over one million years to break down, yet it is infinitely recyclable, able to be remade again and again without losing quality. Recycling glass conserves raw materials, reduces carbon emissions, and transforms what would otherwise be waste into an enduring resource.

Last season, the team collected 17 tons of glass. Just over 3,000 pounds were used to build the tree, while the rest was cleaned, crushed, and sent back into the circular economy. After each festival, the tree’s glass strands are remelted into limited commemorative mini trees for the following year.

“Through Don’t Trash Glass, we’re proving that recycling can be both creative and effective,” said Elliott. “When people see the tree being built from their own recycled bottles, it clicks that what we throw away still has incredible value.”

Where Art Meets the Stars

Set on the shores of Geneva Lake, Yerkes Observatory is regarded as the birthplace of modern astrophysics. Its founding in 1897 marked the first university department dedicated to astrophysics, and it remains home to the world’s largest refracting telescope, which once drew scientific legends including Albert Einstein, Nancy Grace Roman, and Edwin Hubble.

Now, for the first time, every ticket to the World’s Tallest Glass Tree Festival includes the chance to step inside this architectural and scientific landmark. Visitors can explore the Observatory’s marble halls and experience the wonder that connects creativity on Earth with curiosity in the cosmos.

Ticket Options

All tickets include entry to the festival grounds and the Yerkes Observatory’s open house experience. Kids ages 12 and under are free! (Please reserve all children’s tickets online to help organizers plan accordingly.)

• $20 for ages 13 and up
• $30 for a multi-day pass good for all six festival days (non-transferable)
• $150 VIP 4-Pack, which includes on-site parking at Yerkes, four admission tickets, four glass-adding experience passes, and a $5 coupon for the Mack Glass retail shop in the tent
  All additional glass-adding experiences are sold on-site only.

Parking

Festival parking is located at Williams Bay High School (Geneva Street lot). A heated trolley will shuttle guests to and from the Observatory every few minutes. On-site parking is available only for VIP ticket holders.

Festival Dates and Hours
Friday, December 5 – 4 to 7 p.m.
Saturday, December 6 – 12 to 7 p.m.
Sunday, December 7 – 12 to 7 p.m.
Friday, December 12 – 4 to 7 p.m.
Saturday, December 13 – 12 to 7 p.m.
Sunday, December 14 – 12 to 7 p.m.
⭐ Star Topping Ceremony: Sunday, December 14 at 4 p.m.

When: December 5–7 and December 12–14, 2025
Where: Yerkes Observatory, 373 W Geneva St, Williams Bay, WI 53191
Tickets: Starting at $20; kids 12 and under free
Info and tickets: worldstallestglasstree.com

About The World’s Tallest Glass Tree

The World’s Tallest Glass Tree at Yerkes Observatory is a family-friendly public event. We strive to unite the region to celebrate artists, creators, tradespeople, and sciences. Our goal is to provide a welcoming, inspirational event for all people to enjoy during the holidays. By working together, we can increase awareness, make positive changes, and create memorable holiday traditions that will continue for generations to come.

About Mack Glass Community

Mack Glass Community is a 501c3 non-profit organization focused on solving the glass recycling problem through practical and economical solutions, public education, and creative, public art projects. As part of our outreach programming, we work with school and non-profit organizations to offer glassblowing workshops for ages 10 and up.

NOTE: This press release was submitted to Urban Milwaukee and was not written by an Urban Milwaukee writer. While it is believed to be reliable, Urban Milwaukee does not guarantee its accuracy or completeness.