Writer Eric Davis examines a rare piece of agatized coral, found along the Oregon Coast.

On the Oregon Coast, it’s easy to feel like a treasure hunter. Among the hiking, surfing, kayaking, tide pools and amazing wildlife of the region, one of the most beloved local activities is rockhounding. There’s so much to find, and the changing tides churn up new opportunities to explore every day.

So, when looking for agates on the beach, how do you know you’ve found one?

Lava has flowed several times down the Columbia River, aiding in its formation and creating the lava rock base from which agates are made. Silica-rich water settles into the porous lava rock, crystallizes over time and creates an agate.

Both agates and jaspers are part of the quartz family. Agates are translucent gemstones, while jaspers are the opaque variety of the same mineral — chalcedony. Various elements impact the colors of agates. They can be, and often are, clear, but different minerals can also make them look red, orange, yellow, green or blue.

Agates can also be distinguished by their fortifications or banding. An enhydro agate, for example, is a chalcedony nodule with a cavity that still has water trapped inside. You could shake it and hear the sound, or hold it up to a light and see the water inside of it.

If you find something that looks like a gemstone on the Oregon Coast, you’ve most likely found yourself an agate. There’s a spectrum of ways agates can look, and this makes these finds endlessly fascinating.

Now that you know what you’re looking for with agates, if you’re a fan of “The Goonies,” filmed in Astoria, you might be wondering if you need One-Eyed Willie’s map to find a beach that has them. Good news, you don’t, there are many great spots for rockhounding in the Columbia-Pacific region. And don’t limit yourself to the beach shoreline, rivers are great spots too.

Here are a few places to start on a rockhounding adventure.

Short Sand Beach

This popular spot is as known for its agate hunting as it is for surfing. Many venture out to the trail-accessible shore within Oswald West State Park for its waves, but just as many go for the rocks — and the chance to find shipwreck pieces. A local legend has it that a real treasure was buried and never recovered in this area.

Rockaway Beach

Agates have been found in Rockaway Beach, but keep in mind that this coastline is very sandy. While not an ideal spot, agates here are often ones that would surface through the sand periodically, likely along the water’s edge or in stream runoffs.

Manzanita and Neah-Nah-Nie Beach

The terrain of this area is very similar to Rockaway Beach, but more agates can be found here, especially when approaching Neah-Kah-Nie Mountain. Sand dollars, seashells and even shipwreck cargo have also washed ashore along this stretch.

Nehalem River

Hidden gems can sometimes wash up on the banks of this river, known locally for its yellow, orange and deep red carnelian agate, varieties of quartz and even the rare Nehalem blue agate. Marine fossils have been found in the extended Nehalem Spit area as well.

Cove Beach and Arch Cape

These areas are often very sandy, but the south side of Cove Beach toward Cape Falcon can be quite rocky and tends to be where some interesting varieties surface. On the north side, where Arch Cape Creek hugs the headland, is a favorite spot to look around.

Tillamook Head

This is probably the furthest north on the Oregon Coast that one may have luck finding agates. Look for gravel beds on the rocky coast between Chapman Point and Indian Beach.

Columbia River

Home of the Columbia Basin agate, the river’s rocky spits and gravel bars seem to be the best places to look, and it’s helpful to keep a keen eye out for the orange glow of carnelian. Agates can be found in just about any rocky stretch of this enormous historical river.

Damon Point

A notable location for rockhounding near Grays Harbor, Damon Point is a place many know as one of the best places to find Washington beach agates and amazing orbicular jaspers. When hiking the point, know that typically the further out, the better.

Setting out

In addition to these places, there’s always a chance to find agates on unexpected beaches, if you’re willing to look. That leads to some conversation on safety, etiquette and gear.

It’s important to know what you’re getting into before you go rockhounding. Check out and map the area you plan to explore. Use a tide app or chart to know when tides are coming in and going out, and the levels they will be at.

Some places aren’t accessible or safe during high tide. During the highest tides, entire beaches may be only safe to view from a distance.

Know who owns the land you’ll be beachcombing on, as rules can change depending on where you go. Anything collected on a beach is for personal use only. There are daily and annual limits, so check local laws to learn how much can be gathered per state. As a rule, always keep an eye on the water.

Pack lightly but strategically, and plan accordingly for the weather. Light layers, waterproof shoes and gear are helpful. A collection bag is great, and can also carry down anything needed while out on the hunt.

Being a rockhound is also being a steward of the land we look for treasure on. Leave no trace, and even bring an extra bag to pack out any trash found. Most importantly, have fun — agate hunting is memorable for the whole family, although as a fair warning, it becomes a habit. See you out on the coast!