Lime Kiln Point

What is it and why visit?

Coastline and Haro Strait at Lime Kiln Point

Photo by Conner Toth

The lime kiln at Lime Kiln Point State Park

Photo from Washington State Parks and Recreation Commission

When you hear the word ‘kiln’ you probably think of hot flames and brightly colored pottery. What you may not know is that kilns are also used to make ‘lime’, an important ingredient for mortar and cement. Lime Kiln Point hosted a productive cement industry between 1860 and 1935, with workers laboring as much as ten hours a day at the kilns to produce thousands of barrels of lime per year. This popular 41-acre State Park is also home to an historic lighthouse that dates back to 1919. The lighthouse is still used for navigation by ships sailing through Haro Strait. The beautiful rugged coastline here makes Lime Kiln Point an excellent place—some say one of the best in the world—to watch orcas, gray whales, and porpoises during their yearly migration from May to September. Settle down at one of the viewing areas and enjoy the spectacle!

Be aware that this area is part of a tsunami hazard zone. Go here to learn more about tsunami hazards in Washington.

Process of turning limestone to lime

WGS/DNR

The kilns at Lime Kiln Point were used to create lime from limestone. Limestone is a calcium-rich rock made of the shells of microscopic sea creatures. When limestone is heated to a temperature of about 1,600°F (about four times hotter than a standard oven!), the carbon dioxide in the rock burns off, turning the limestone into a toxic material known as ‘quicklime’. When quicklime is mixed with water, it forms a much less hazardous white powder called ‘lime’. Mixing this powder with more water as well as sand, volcanic ash, or crushed rock produces mortar, the sludge that holds bricks together. Lime is also useful in agriculture as a way to neutralize soil that is too acidic for growing crops.

The San Juan Islands were an ideal place to produce lime due to an abundance of both limestone and wood. Douglas fir provided excellent fuel for keeping the fires of the kilns burning. The many limestone quarries on San Juan Island provided the raw material for feeding the kilns. You can see outcrops of limestone with fossils at Lime Kiln Point. The fossils and limestone are around 280 to 260 million years old.

A busy summer day at Lime Kiln Point State Park

Photo by Dan Coe, WGS/DNR

The presence of limestone on San Juan Island indicates that this piece of Washington was once under shallow water. The San Juan Islands are made of rock groups known as terranes, broken-off pieces of Earth’s crust that have been moved from where they originally formed. Continental drift transported the terranes towards western Washington, carrying them thousands of miles across the ocean. Eventually, the terranes were scraped off onto the North American plate along what is now the modern Cascadia subduction zone.

LEARN MORE ABOUT:

• San Juan Islands