Understanding Boulder Sizes and Stone Types in Northern Michigan

Randy
1 day ago
3 min read

Choosing the right boulder is one of the most important decisions in any landscaping or shoreline project. The size, weight, and type of stone all affect the appearance, durability, and long-term performance of retaining walls, seawalls, patios, fire pits, and shoreline stabilization projects.

Northern Michigan is known for its incredible variety of natural stone, much of it deposited by glaciers thousands of years ago. From rugged granite boulders to weathered limestone and colorful fieldstone, each stone has unique characteristics and ideal applications.

At Boulder Brothers LLC, we work with many different stone types and boulder sizes to create projects that are both structurally sound and visually impressive.

Common Boulder Sizes

Boulders are typically measured by their approximate diameter and sold by the ton. The larger the stone, the more equipment and planning are required for installation.

12–18 Inch Boulders (Accent Stones)

Weight: 100–400 lbs
Best for: Garden beds, edging, small water features, and decorative accents
Advantages: Easy to place and reposition, affordable, and great for adding natural character to landscaping.

18–24 Inch Boulders

Weight: 400–1,000 lbs
Best for: Small retaining walls, step transitions, and shoreline accents
Advantages: Provide a stronger visual presence while still fitting well in residential landscapes.

24–36 Inch Boulders

Weight: 1,000–3,000 lbs
Best for: Retaining walls up to several feet tall, natural stone stairs, and medium shoreline projects
Advantages: One of the most versatile size ranges for structural landscaping.

36–48 Inch Boulders

Weight: 3,000–7,000 lbs
Best for: Large retaining walls, seawalls, and statement landscape features
Advantages: Excellent stability and a dramatic natural appearance.

48–60+ Inch Boulders

Weight: 7,000–15,000+ lbs
Best for: Major shoreline stabilization, commercial projects, and high-end custom landscapes
Advantages: Maximum structural strength and an impressive, one-of-a-kind look.

Matching Boulder Size to the Project

Why Bigger Isn’t Always Better

Many homeowners assume the largest possible boulder is the best choice. In reality, the correct size depends on:

Wall height
Soil conditions
Drainage design
Available space
Equipment access
Overall landscape style

A properly engineered wall using correctly sized stones will outperform a poorly built wall made with oversized boulders. Stone placement, base preparation, and drainage are just as important as the size of the rock itself.

Choosing Stone for Northern Michigan Conditions

Because of harsh winters and frequent freeze-thaw cycles, we typically recommend:

Granite for maximum durability and structural applications
Limestone for classic waterfront projects
Fieldstone for natural, rustic landscapes
Quartzite for premium custom installations
Sandstone for warm, natural step and accent features

These stones have proven themselves over decades of exposure to Northern Michigan weather.

Professional Boulder Selection and Installation

At Boulder Brothers LLC, we carefully select each boulder for size, shape, and character. We look for stones that lock together properly, provide long-term stability, and create a natural appearance that fits the property.

Whether we’re building a retaining wall, installing natural stone stairs, repairing a seawall, or creating a custom waterfront feature, our goal is always the same: use the right stone, in the right size, installed the right way.

Final Thoughts

Northern Michigan offers some of the most beautiful natural stone in the country. Understanding the differences between granite, limestone, sandstone, fieldstone, quartzite, and basalt—and knowing which boulder size is appropriate for your project—helps ensure your investment will remain beautiful and structurally sound for decades.

If you’re planning a retaining wall, shoreline project, patio, or custom landscape feature, Boulder Brothers LLC can help you choose the perfect stone and boulder size for your property.