The best places to find rocks are where they’re already exposed. Look for outcrops – natural rock exposures on hillsides, bluffs, or stream banks. Cliffs, canyon walls, and eroded hills often have loose rocks at their base. Road cuts (those rock faces revealed by highway construction) can be a goldmine for accessible rocks​. Just be sure to pull over safely and watch out for traffic if collecting along a roadside.

Quarries (active or abandoned) are excellent sources as well​, since they intentionally expose rock layers; you usually need permission to enter, but some gravel or stone quarries might let you take surplus rock rubble. In general, hills and steep ground are better than flat plains for finding rocks, because flat areas often have deep soil covering the bedrock​.

So, head for the nearest high ground or cut slope in the area you’re exploring.

Old riverbeds and seasonal washes often have concentrations of rocks.

If you find a dry creek bed, especially one that runs during winter rains, it likely has deposited cobbles and gravel that you can pick through. Desert washes, for example, may be littered with stones carried from nearby mountains during flash floods. These can be great places to collect a variety of smoothed rocks without much digging. Just ensure you’re not on private land (use maps or BLM info to check).

Also, be mindful of the weather – don’t venture far into narrow washes if there’s any chance of sudden rain upstream (flash flood danger). But on a clear day, wandering a dry stream channel can yield plenty of landscaping rock with minimal effort (most will be lying right on the surface).

As mentioned in regional notes, beaches (lake or ocean) and riverbanks are prime spots for rounded stones. Many people simply walk along a river or lake shore and pick up attractive pebbles or cobbles for their gardens. Public fishing access points or bridge crossings over rivers often have trails down to gravel bars.

On the coast, public beach accesses (outside of parks) allow combing for pebbles – a small bucket of ocean-polished stones can usually be taken for personal use, but don’t fill up a truckload from one beach. A good strategy is to collect a little from different spots so no one area is depleted.

Note: In California state recreation areas, rockhounding is explicitly limited to within the wave action zone on beaches and flooded stream gravel bars​, highlighting that these are considered renewable rock sources. So targeting those kinds of locations is both productive and often permitted.

California has numerous famous rockhounding locations known for specific minerals (like garnet hill, opal mines, etc.). While many of those are geared toward gem/mineral collectors, they can also be sources of general landscape rock. For example, the Mojave Desert has the Wiley’s Well area for geodes and the Cady Mountains for jaspers, and Northern California has streams where jade and serpentine can be found.

Use guides or online forums to identify such places. The Bureau of Land Management sometimes designates “rockhound areas” – for instance, the Chambless area in the Mojave for fossil-bearing limestone, or Saviah Peak area for agate nodules​. Visiting these spots can be fun because you know you’re allowed to collect and likely to find something interesting. However, some popular sites may already be picked over of the best pieces, and remember that anything truly rare or valuable you find is more a bonus than guaranteed.

Always verify current access rules; some sites on BLM land are open, others might require a simple permit or have vehicle restrictions.

An often-overlooked source of free rocks is human construction and landscaping waste.

If you notice a construction project (like a new home foundation, roadwork, or trenching) where they are digging up lots of rocks, sometimes the contractors have piles of boulders or rubble they need to dispose of. It doesn’t hurt to politely inquire if they have excess rocks – they might let you take some off their hands. Similarly, check if your local public works or utilities ever have to excavate rock; city maintenance yards occasionally accumulate rock from projects.

Even farmers or landowners clearing fields might have rock piles. Online community boards (Craigslist, Facebook Marketplace) often have listings for “free rocks” or fill dirt with rocks – you haul it, you can have it. Just be cautious to inspect such rocks if you want them for decor (they might be mixed with debris or not the look you want) and always ensure the offer is legitimate.

Many National Forests in California have rivers or creeks with great rock deposits (think of all those Sierra Nevada rivers). These areas are usually legal to collect in small amounts. For example, in the Sierra National Forest or Plumas NF, you can hike along creeks and gather a backpack of nice stones. Because National Forest land is public, non-commercial collection of rocks is allowed as long as you’re not in a designated scenic or wilderness area that prohibits removal. Still, it’s wise to check with the local ranger station if they have any guidelines. Some forests issue free use permits if you want to collect a larger volume for landscaping (like a truckload), as part of their forest products permits – it’s worth asking if you need one for large quantities​.

Look for areas where natural forces gather rocks. Foots of hills (talus slopes) often have broken rock fragments. The inside bends of rivers accumulate gravel, whereas outside bends have finer sand. Along a hillside, look in gullies or small ravines where runoff might expose stones. Places with sparse vegetation often indicate rocky ground (since thick soil supports more plants).

If you’re after flat stones for pathways, target sedimentary rock areas; if you want rounded boulders, aim for riverbeds or glacial deposit zones (the Sierra foothills have many glacial erratics and smooth glacial cobbles).

Also, simply keep your eyes open while driving or hiking: you might spot a pile of interesting rocks by the road, an eroding bank with appealing stones, or even landscaping in public areas where a few loose pieces are scattered (though don’t take rocks from someone’s landscaped property or maintained public gardens).