MMGM Annual Tent Sale!

When: September 6 & 7, 2025
Time: 10 a.m. to 4 p.m.

From rare Maine specimens to minerals from around the world, the museum’s annual tent sale is back! Once a year, the back parking lot at MMGM transforms into something magical: a sprawling pop-up market under two big white tents. Curious shoppers will find tables overflowing with treasures waiting to be discovered. Come for the bargains, stay for the thrill of discovery!

A gleaming hunk of Maine tourmaline might catch your eye. Or maybe you’re looking for minerals from faraway corners of the globe. Flip through stacks of well-loved and collectible books from our library — some available for just a few dollars! Browse bins of games, toys, home goods, and more from the museum store, all marked down and ready for a new home. 

For rockhounds, collectors, and anyone curious. The tent sale is your chance to unearth something rare, beautiful, or delightfully unexpected — at a discount!

What you’ll find:

• Rare minerals: from rare Maine specimens to global finds, many never before offered in our store
• Discounted books: including collectible and out-of-print titles from our library
• Clearance treasures: games, toys, home goods, and unique store items at deep discounts
• One-of-a-kind finds: some unusual, some rare, all ready to be discovered
• Discounts galore: everything is priced to move!