California Metal Detecting Laws: Your Guide to Treasure Hunting in the Golden State

California is legendary for treasure—think gold rush dreams, Spanish missions, shipwrecks, and old coins just waiting to be found. Whether you’re a weekend warrior or a first-timer with a metal detector you got for your birthday, you’re probably itching to see what’s buried beneath the sand, soil, or surf. But here’s the kicker: California’s metal detecting laws aren’t as simple as “finders keepers.” There are rules—sometimes a lot of them—depending on where you want to hunt and what you hope to keep.

Who Owns the Land? That’s Where the Rules Begin

The first thing to figure out is who controls the land. In California, you’ve got public beaches, state parks, federal lands, city parks, schoolyards, and private properties. Each one comes with its own set of rules, so what’s legal at the beach might get you in trouble up in the redwoods.

Federal Land: Strict Rules and No-Nonsense Enforcement

Huge parts of California are owned by Uncle Sam—national parks, forests, monuments, and BLM land. These are some of the strictest areas when it comes to metal detecting.

National Parks & Monuments: No metal detecting allowed. Not for fun, not for lost rings, not for anything. Removing artifacts—or even disturbing the soil—can bring heavy fines, confiscation of your equipment, or even federal charges. No joke.
Bureau of Land Management (BLM): There’s a little more wiggle room here. Detecting for modern lost items is generally okay, but you can’t remove anything “historic” (over 100 years old) or dig up artifacts. Also, you must avoid archaeological sites, and digging up old bottles or relics is off-limits. Always double-check with the local BLM field office.
National Forests: Rules are similar to BLM—detecting for modern items is typically allowed, but historical artifacts are protected by the Archaeological Resources Protection Act (ARPA). Dig carefully, fill all holes, and avoid any ruins, foundations, or places that look like they might be historic.

It can be confusing, since rangers sometimes interpret rules differently. When in doubt, call ahead or check online.

California State Parks and Beaches: Mixed Bag

If you’re picturing California’s famous beaches or grassy parks, you’re in luck—sort of. Metal detecting is allowed in many (but not all) California State Parks, especially on beaches, but with important restrictions.

You can usually metal detect on state beaches—places like Huntington, Santa Monica, and Pismo Beach are popular spots for detectorists hunting for coins, rings, or lost jewelry.
In most inland state parks, you’ll need written permission from the park superintendent or manager. Some parks allow detecting only in specific areas (like campgrounds or picnic zones) and ban it in sensitive habitats or near historic sites.
Artifacts: If you find something over 50 years old (California’s threshold for “historic”), you’re required by law to leave it where it is and alert park staff. Even “harmless” items like old nails, glass, or buttons can qualify.

Bottom line: Check the rules posted at each state park, or call the ranger station before you go.

City Parks and Local Land: Sometimes Easy, Sometimes Not

Many California cities and counties allow metal detecting in public parks, as long as you don’t damage turf or landscaping. Some places, especially larger cities like Los Angeles and San Diego, have their own municipal codes. You might need to avoid athletic fields, stay clear of playgrounds, and fill in all holes neatly.

Always check with the local parks and recreation department. Some require written permission or a simple permit.
If you see signs saying “No Metal Detecting” or “No Disturbing the Grounds,” take them seriously. Ignoring the rules can get parks closed to everyone.

Schools, Churches, and Other “In-Between” Places

School grounds are almost always off-limits during school hours for safety and privacy reasons. Some districts might allow metal detecting outside of school hours, but you’ll need written permission from the principal or district office. The same goes for church properties and sports fields—always ask before you start.

Tip: Sometimes a friendly request and promise to fill your holes will get you further than you’d expect.

Private Property: The Golden Ticket (With Permission!)

On private land, it’s up to the owner. If you have written permission, you’re good to go—just be sure you agree on what happens to any finds (especially if you stumble across something valuable). California law doesn’t care what you and the property owner agree to, as long as you’re not removing protected artifacts or trespassing.

Always get it in writing—even a quick text can save misunderstandings later.

What Can You Legally Keep in California?

Here’s where the rules get a little tricky. California has a lower threshold than federal law: artifacts over 50 years old are considered “historic” and protected, especially on public land. You’re supposed to leave them in place and notify park staff or the land agency.

Modern Lost Items: If it’s a recent coin, ring, or phone, and you found it legally, you can keep it. Good karma to try returning valuables, especially if there’s an ID or engraving.
Historic Artifacts (50+ years): These are off-limits on public land. Removing them can bring fines, and sometimes you’ll have to return them if you post about your find online!

On private property, finds over 50 years old might technically be protected if they’re of major historical value, but in most cases, it’s up to you and the owner.

Gold Prospecting: Still Legal, Still Tricky

California is famous for gold, and yes—you can still detect for nuggets and flakes on much BLM and forest service land. The catch? You must avoid private property, active mining claims (always check claim maps), and protected rivers or streams. Dredging and large-scale mining have stricter rules, but casual detecting and panning are generally allowed in “open” areas.

A quick stop at a BLM office or a look at the state mining claims map can save you a lot of headaches (and angry miners).

Digging Etiquette: How to Keep the Hobby Alive

Nothing gets metal detecting banned faster than leaving a mess. Fill your holes, take all your trash (even rusty nails and bottle caps), and respect landscaping. If someone asks what you’re doing, explain with a smile—most people are just curious. If you see a fellow detectorist, say hi! California’s a big state, but the hobby’s a small world.

Stories from the Golden State: Finds, Fines, and Fun

There’s no shortage of California stories: someone finding a gold ring at Huntington Beach, a lost Spanish coin in an old orchard, or even a kid digging up a class ring at the park and returning it to a grateful grandparent. But there are also tales of people who posted a cool find on social media, only to have the authorities show up and claim it as a protected artifact!

The lesson? Know the rules, play it safe, and the stories you tell will be the good kind.

Quick Tips for California Detectorists

Never detect on federal land, national parks, or Native American reservations without written permission.
Check state and local park rules before you start. When in doubt, call the ranger or park office.
Always get written permission for private land, and clarify what happens to your finds.
Be careful with “old stuff”—leave artifacts in place and report anything important to park staff.
Respect the land, fill your holes, and pick up all trash (even if it’s not yours).
Gold prospecting is still legal—just avoid claims and protected waterways.

Final Thoughts: Respect, Research, and the Joy of the Hunt

California is a treasure hunter’s dream, but the laws can be a little wild. Do your research, get your permissions, and treat every spot like you want to be invited back. With a little effort and respect, you’ll find that the Golden State still has plenty of treasures waiting just beneath the surface.