There were many gold rushes; I assume your question is about the California Gold Rush of 1849. In this case, enthusiasts were seeking extensive, widespread deposits of surface or near-surface gold dust and nuggets. Groups of men (and sometimes women) would then wash gravels and dirt - often excavated from stream beds - and then use tweezers to remove visible bits of gold. Little or no expertise was needed. Places with little gold were abandoned for the "next place"; good deposits were exploited until the gold was exhausted, at which point the team would move to the "next place." Prospecting and mining were practically simultaneous.

As surface deposits became exhausted and society - and land claims - became more complex, prospecting increasingly turned to the location of intense, largely subsurface deposits of gold. This began a second phase of the Western gold rush and resulted in several additional "rushes" in the hinterland. In these cases, prospectors often did not have the financial resources or the technical expertise to excavate underground. They often found veins or "lodes" (using a Cornish dialect term for vein) that were located because they erupted at the surface. Prospectors were often like the original miners of '49; they used a simple level of technology to "work" the surface ore. If prospects for subsurface ore seemed promising, discoverer(s) would try to sell the claim so a second phase of corporate development could be pursued.