Horse clams are one of the more larger shellfish found on Puget Sound and Hood Canal beaches (Photo submitted by Shane Kempf)

Head to the many public beaches of Washington and discover the joys of shellfish gathering

In the second of a four-part series on shellfish we’ll dig into butter and horse clams that can be found on public tidelands in Puget Sound, Hood Canal as well as best practices for gathering and eating clams


Here in Washington, we are lucky to live somewhere where we can forage delicious, healthy seafood from publicly owned tidelands.

With over 350 open areas and about 275 low tides per year, there are endless opportunities to harvest on public lands. Bivalve shellfish are a nutritious local protein.

Puget Sound tidelands and coastal beaches host many varieties of clams. Razor clams are only found on the outer coast because they require a high wave energy sandy beach to survive, and the recreational season usually occurs in fall through spring of year. In Puget Sound and Hood Canal, harvesting seasons vary by beach and there is a plethora of delicious species to discover.

In this second of a four-part weekly series, we will focus on how to harvest, store, and prepare butter and horse clams found in Puget Sound and Hood Canal.

Butter clams are another shellfish found along Puget Sound and Hood Canal beaches.

Butter clams

Many people pursue butter clams for their large size and sweet, mild meat. Butters are usually harvested at 3–4 inches across the longest part of the shell but may grow as large as 6 inches. Minimum legal size is 1 ½ inches (38mm) across the longest part of the shell. Butter clam harvesters should carry a scale into the field to ensure they do not exceed the daily limit of up to 40 clams, not to exceed 10 pounds in the shell. With larger butters, harvesters are likely to achieve 10 pounds with 18–22 clams. Butters usually live deeper in the beach substrate and start at lower beach tidal elevations, closer to low tide lines.

They are usually buried 12–18 inches below the surface in mixed sand, mud, and gravel, but harvesters can also find butter clams in cobble. Shells are thick and chalky white but may be stained black, blue, or even pink. Butter clams only have concentric rings marking their shells. If you take small butter clams (1–2 inches) these can be processed like steamer clams and cooked with them. Larger clams are usually removed from the shell to cook their meats, or they are BBQed using the shells for cooking vessels.

Butter clams are not known to rebury themselves after they have been dug. If you decide not to take butters you have uncovered, please place them about 10 inches deep in the empty hole with the siphon end up. You can usually find the siphon end by looking for the slight gape on the less pointy end of the shell. Place a clump of soil or rock against the shell to help keep it upright, then carefully cover with material from your excavated hole.

Butter clam’s uptake and hold biotoxins longer than other clams. The Washington Department of Health (DOH) certifies growing areas and establishes recreational harvest advisories based on field sampling. Always check current DOH status the same day you plan to harvest shellfish.

How to process butter clams: You can clean butters by cutting them free of the shell using a sharp paring knife to sever both adductor muscles. Adductors are located at the top and bottom of the clam, attached to both shells. Slip your blade between the muscle and the shell for a clean cut. Move quickly as the clam will immediately begin to close its shell tightly. Remove some of the stomach contents if you wish. The darker greenish black algae can be seen in the stomach area. Dark stomach contents are fully edible and are naturally rich in Vitamin E.

Store meat on ice or in the fridge immediately. Some people also choose to cut off the black tip of the siphon, but this is not necessary. Alternatively, if you plan to BBQ the clams, cut directly through the clam tissue, and butterfly the shells with half the meat on either side of the shell. You may need to rinse some sand and grit from tissues along the margins of the shell. Add your favorite sauce and clam halves will cook in the shell cups. Meats can also be steamed out of the shells and chopped for use in a wide range of recipes.

A happy digger shows off a pair of horse clams. (Photo submitted by Kristina Wilkening)

Horse clams

There are two species of horse clams in Washington, the fat gaper (Tresus capax) and Pacific gaper (Tresus nuttallii). Both species are covered by the same daily bag limit and can be processed and cooked similarly. Diggers should refer to the Washington Department of Fish and Wildlife (WDFW) regulation pamphlet on specific daily limits for horse clams and other specific rules that apply to horse clams. Broken clams will not survive but are still excellent for harvest. Shells are thin and sharp and usually have a diagnostic brown shellacking around the shell margin called the periostracum.

Horse clams live 1–2 feet below the surface and do not rebury themselves well. If you do need to rebury horse clams that have been accidentally dug, place the shell at least 12 inches below the surface and press sand against the shell as you backfill the hole. Be careful the clam does not tip to its side.

Horse clams can be mistaken for geoduck but are easily identified by the leathery plate-like flap on the tip of its siphon. These plates are often growing algae and have barnacles set on them. Geoduck have smooth, fleshy siphon tips and shells are buried up to 3 feet or more in the beach. Horse clams can retract almost all their siphon into their shell, but geoducks cannot.

Horse clams and geoducks do not “run” from harvesters. Instead, they are simply retracting their siphons closer to their shells. Once clams have matured, their shells tend to stay in one place and the digging foot becomes recessive.

How to process horse clams: Cut off the siphon and set aside. Slide a sharp paring knife along the inner edge of the shell and cut the meat free by severing the adductor muscles. Adductors are located at the top and bottom of the clam, attached to both shells. Cut out most of the stomach area and save the softer mantle meat for cooking as you choose (quick pan sear, chowder, etc.). You will find a clear plastic-like straw (or crystalline stile), discard this along with the gut ball. (Or add to your frozen crab bait stash.)

It is not uncommon to find tiny pea crabs in horse clams. These soft-bodied crabs serve in a commensal relationship with the clam, functioning as a cleaning service in the mantle. Sometimes you will find mated pairs emerging from clams as you clean them. To remove the leathery membrane from the siphons: Cut off the tip of the siphon to remove the leathery plates.

Plunge the siphon into very hot water (not quite boiling) for about 30 seconds, and then slip the leathery membrane off the siphon as if removing a nylon stocking. Split the siphon up the tubes and rinse away any sand. Horse clam siphon meat makes phenomenal ceviche. It can be pounded for delicious fritters or used like any other tougher clam meat (chowder, pasta dishes, clam cakes, etc.).

Transporting and storing butter and horse clams: Store clams in a cooler with ice until you reach the location where you will clean or cook the clams. It is very important to keep clams cool until you cook them. Be careful clams do not sit in melted ice water while transporting. I prefer to use freezer blocks over freshwater ice cubes, so water melt is not an issue. If using fresh ice, keep clams separated from bag with a dish towel or layer of cardboard.

Live large butters will store for about 3 days and horse clams will store for about 2 days if kept wrapped tightly in a damp dishcloth in the refrigerator. Wrapping each clam’s shell with a rubber band will improve storage. Deeper dwelling clams are used to being buried in the beach where the substrate would exert pressure against the shell. Wrapping them tightly in damp dish towels and binding with rubber bands will mimic this pressure. Clams will gape slightly while stored but should respond by moving their siphons or closing their shells when handled.

(Note: Do not store butter or horse clams in water in the refrigerator as they will suffocate from lack of oxygen and die. As a rule, except for during purging, do not store any clams in water for any length of time.)

NEW! Cornucopia of shellfish recipes

We are lucky to live in Washington where you’re able to forage delicious, healthy seafood from publicly owned tidelands.

We’ve compiled a very extensive list of delightful recipes to provide tips and advice on how to cook local shellfish. Be sure to visit the WDFW’s shellfish recipe page for all the details. In the coming months we plan to expand our recipe page to include not just seafood but many other dishes that’ll be sure to wow your guest at the dining table!

If you go

Before heading to the beach, be sure to read the first part of our shellfish gathering series where we go over details and helpful information on licenses; regulations; current seasons for various shellfish; water quality and closures; a shellfish safety map; tide charts; gear list; prepping shellfish to eat; and a wide-range of links to a list of resources.

(The shellfish gathering information in this series was written and compiled by Camille Speck, the WDFW Puget Sound Intertidal Bivalve Manager)



The Washington Department of Fish and Wildlife

The Washington Department of Fish and Wildlife is dedicated to preserving, protecting and perpetuating the state’s fish and wildlife resources.