Pismo Beach·Clamming

California regulates the recreational harvest of Pismo clams (Tivela stultorum) under the California Code of Regulations, Title 14, Sections 29.20 (general clam provisions) and 29.40 (Pismo clam-specific rules), administered by the California Department of Fish and Wildlife. Violations carry meaningful penalties — fines for undersized clams can run to roughly $170 per clam, and citations are actively issued at Pismo Beach.

For Pismo Beach (San Luis Obispo County), every clammer must:

• Possess a valid California sport fishing license (anyone 16 or older)
• Carry an accurate, rigid measuring device sized to 4.5 inches
• Take only clams measuring at least 4.5 inches in greatest shell diameter
• Limit the daily take to 10 clams per person
• Use a separate container from any other clammer
• Clam only between one half-hour before sunrise and one half-hour after sunset
• Immediately rebury any undersized clam, two inches deep, hinge upward, in or near the hole from which it came

The sections that follow expand each of these requirements with citations to the underlying regulation.

Anyone 16 years of age or older who takes any fish, mollusk, invertebrate, amphibian, reptile, or crustacean in California waters must have a valid California sport fishing license. This requirement applies fully to Pismo clamming. The license must be in the harvester’s immediate possession while on the beach.

Where to obtain a license

Licenses are issued by the California Department of Fish and Wildlife and may be purchased online, at licensed sporting-goods retailers, or by phone. The CDFW License App allows a digital license to be displayed on a phone in lieu of a paper copy.

• CDFW Online License Sales
• By phone: (800) 565-1458

Ocean Enhancement Stamp

An Ocean Enhancement Stamp is required for ocean fishing (including clamming) south of Point Arguello, in northern Santa Barbara County. Pismo Beach is north of Point Arguello, so the Ocean Enhancement Stamp is not required at Pismo. Clammers who plan to harvest farther south should check the requirement against their destination.

Free Fishing Days

California designates two annual Free Fishing Days on which no license is required to fish or clam, though all other rules — size limits, bag limits, hours, and reporting where applicable — remain in full effect. CDFW announces the current year’s dates each spring; current dates are posted at the CDFW Free Fishing Days page.

Minimum size

Title 14, § 29.40(c) sets two minimum sizes for Pismo clams, defined by the boundary between San Luis Obispo and Monterey counties:

• 4.5 inches in greatest shell diameter, south of the boundary — this is the standard at Pismo Beach
• 5 inches in greatest shell diameter, north of the boundary

The measurement is taken across the longest dimension of the shell. A clam below the minimum is undersized and must be returned to the sand under the rebury rule.

Daily bag limit

Title 14, § 29.20 sets a daily bag limit of 10 Pismo clams per person. The possession limit is the same as the daily limit; no person may transport more than 10 clams in a single day, even across multiple locations.

Container rule

Each clammer must keep clams in a separate container. Commingling clams from two or more harvesters in a single bag, bucket, or sack is prohibited under § 29.20. The container rule exists so that a warden can verify each individual’s catch against that individual’s license and bag limit.

Sale prohibited

The sale of California-harvested Pismo clams has been illegal since the closure of the commercial fishery in 1947. The current recreational fishery is for personal consumption only.

Title 14, § 29.20 requires that every clammer taking any clam with a minimum size limit (which includes Pismo clams) possess an accurate, rigid measuring device sized to that minimum, while clamming. The device is not optional or advisory; it is a separate legal requirement alongside the license and the size limit itself.

"Rigid" excludes flexible rulers and tape measures. "Accurate" means dimensionally true to 4.5 inches. The most common implementation is a metal or hardwood gauge sized exactly to the legal minimum, often mounted to the handle of a clam fork so that each clam can be measured at the moment it leaves the sand.

Gauges of this type are manufactured by CXB-Designs, the publisher of this resource, and by other makers. Any rigid gauge calibrated to 4.5 inches is legal; the law specifies the function, not the manufacturer.

Every undersized Pismo clam encountered — whether dug intentionally or surfaced incidentally — must be immediately reburied. The proper technique is specified in CDFW guidance and reinforced by Cal Poly research:

• Place the clam in a hole at least two inches deep
• The hinge ligament (the dark bump where the two shells meet) should face upward
• The hinge should point toward the ocean
• If the original hole is still open, that is the preferred location

The rebury rule has practical importance beyond compliance. Pismo clams take roughly nine to twelve years to reach the 4.5-inch legal size, according to Cal Poly Marine Conservation Lab researcher Marissa Bills. Of every several thousand clams seen on the beach, only one or two are typically of legal size. The remainder are juveniles whose survival is the basis of any future fishery. A clam reburied correctly burrows back into the sand within minutes; a clam left exposed is taken by gulls or dries in the sun.

Reburying clams that surfaced naturally (as occurs in the periodic mass-surfacing events at Pismo Beach) is generally not recommended — surfacing is normal behavior and the clams will rebury themselves. The rebury rule applies specifically to clams the harvester has dug.

Title 14, § 29.20 limits the take of Pismo clams to a daylight window: one half-hour before sunrise through one half-hour after sunset. The window is anchored to local civil twilight at the harvester’s position, not to a fixed clock time, and shifts with the calendar.

An additional provision makes it unlawful to be on a clam beach with any instrument capable of being used to dig clams during closed hours, regardless of whether digging is actually taking place. A clammer arriving on the beach with a fork an hour before legal start time has already committed a violation.

The Tide Almanac on this site lists low-tide times against sunrise and sunset, automatically excluding any tide that falls outside the legal window.

Pismo Beach: open year-round

Title 14, § 29.40(a) opens Pismo clamming year-round in all California counties south of Monterey, including San Luis Obispo County. There is no closed season at Pismo Beach.

Monterey and Santa Cruz counties: seasonal

For comparison, Pismo clams in Monterey and Santa Cruz counties are subject to a closed season from May 1 through August 31; harvest is permitted only from September 1 through April 30. This restriction does not apply at Pismo Beach itself.

Marine Protected Areas

Title 14, § 29.40(d) and § 632 prohibit the take of clams within designated state marine reserves and certain other marine protected areas. Pismo Beach itself is not within an MPA that prohibits clam take, but harvesters working other Central Coast beaches should consult the CDFW Marine Protected Areas map before assuming an area is open.

The regulations specify what tools may be used. The list is permissive of common digging implements and explicitly excludes a few categories:

Permitted

• Spades, shovels, hoes, rakes
• Potato forks (the standard clam fork)
• Knives, when taking clams while diving
• Hands

Prohibited

• Spears or gaff hooks — banned outright by § 29.20
• Hydraulic pumps — explicitly disallowed
• Power-driven mechanical devices generally

The Equipment page covers the practical selection of clam forks, gauges, and supporting gear in detail.

Pismo Beach is a popular state park with active patrol. Both California Department of Fish and Wildlife wildlife officers and the Pismo Beach Police Department enforce clamming regulations. State Parks rangers also patrol and report violations. The local community is invested in the recovery of the clam population, and clammers should expect that anyone working the beach is being observed.

Recent enforcement

In 2024, CDFW Wildlife Officer Brian Meyer reported approximately 80 citations for clamming violations had been issued through July, exceeding the prior year’s pace. A single enforcement action that year resulted in citations for three individuals collectively in possession of 120 undersized clams.

Penalties

Fines for undersized clams can reach roughly $170 per clam, depending on the size of the clam and the location of the offense. Bag-limit violations, license violations, and possession in closed hours each carry their own penalties. A clammer cited for ten undersized clams faces fines that can total well over a thousand dollars.

Reporting violations

The CDFW operates a confidential anonymous tip line for fish and wildlife violations:

Beyond the harvest regulations administered by CDFW, the consumption of Pismo clams is subject to public health monitoring administered by the California Department of Public Health. CDPH issues quarantines and health advisories when laboratory monitoring detects elevated levels of paralytic shellfish poisoning toxins or domoic acid in shellfish samples from California beaches.

These advisories are not part of the take regulations — a clammer may legally harvest during a CDPH advisory — but eating contaminated clams is a serious health risk. Cooking does not destroy these toxins. Before any consumption, every harvester should check the current state of biotoxin advisories. The Safety page provides the full treatment.

This page is reviewed annually, or sooner when a regulatory change is brought to our attention. The substantive content above reflects California regulations in effect as of the date noted below.

Regulations can change between reviews. Emergency closures, season adjustments, and rule amendments are issued at the discretion of CDFW and can take effect on short notice. Before any clamming trip, every harvester should confirm the current rules directly with the California Department of Fish and Wildlife.

• CDFW Invertebrate Sport Fishing Regulations
• CDFW Fishing and Hunting Regulations index
• CDFW Pismo Clam Enhanced Status Report
• Title 14 California Code of Regulations, § 29.40 (Pismo Clams)
• Title 14 California Code of Regulations, § 29.20 (General Clam Provisions)

Errors of fact or outdated citations on this page should be flagged for correction.