Hardrock Mining – This mining method requires digging into solid rock to find minerals in their ore form. The simplest form is utilizing picks and shovels, but rock drills and dynamite were often used as well. Shafts and tunnels might go straight down into the ground or advance horizontally into a mountain faces. Shafts and tunnels were often supported with large timbers to prevent cave-ins, but accidents were prevalent in early mining days. Deep shafts were generally accompanied by a head frame standing above them to support the hoists. These types of mines almost always eventually flooded as they got closer to the water table, at which times pumps were used to remove the water. In some cases; however, there was so much water that a mine would have to be abandoned.
Placer Mining – Pronounced plăs’ər, this type of mining involves the obtaining of minerals from placer deposits by washing or dredging. The word placer comes from the Spanish word meaning “sandbank,” and refers to mineral deposits, particularly gold and gemstones found in alluvial deposits — sand and gravel found in modern or ancient stream beds. This is the oldest method of recovering gold from alluvial deposits and is also the easiest, including panning, sluicing, using a rocker, or if lucky enough, simply picking up what lies on the ground. Placer mining also includes dredging and hydraulic methods. Placer mining takes advantage of gold’s high density, which causes it to sink more rapidly from moving water than the lighter materials it is found in.
Dredging – The most important placer-mining method today, this involves the use of a floating boat or barge with either a series of buckets to scoop gravel or a suctioning apparatus to vacuum gravel from the bottom of a creek or river. The most common type of dredge used in gold placer mining in the early 1900s was a bucket-ladder dredge that is a chain of continuous buckets rotating around a rigid adjustable frame called the ladder. The use of dredges is also accompanied by the use of sluices to separate the gold from gravel and debris.
Hydraulic Mining – Another type of placer mining, this utilizes high-pressure water that is sprayed at an area of rock and/or gravel, which breaks up the rock and dislodges ore and placer deposits. The water/ore mixture is then milled. Due to its destructive forces, this type of mining has been outlawed in most areas.
Panning – This is the simplest form of placer mining. The most often used technique of the 19th-century miners, prospectors place a few handfuls of sand and gravel in a large pan along with water and shake it around until the gold particles or other heavy metals settle to the bottom of the pan.
Then the lighter sand, mud, and gravel was washed over the side of the pan, leaving the gold behind. When gold was found, the miners would then move on to equipment such as sluices and rockers so that they could handle a higher volume of sand and gravel. Eventually, these easy to find minerals would be worked out, and higher forms of technology would be utilized to get at the gold, including hydraulic mining and dredging.
Sluicing – A slightly sloping wooden trough called a box sluice, or a ditch cut in hard gravel or rock called a ground sluice, is used as a channel along which gold-bearing gravel is carried by a stream of water. Riffles placed along the bottom of the sluice cause the water to eddy into small basins, slowing down the current so that gold may settle.
Open-pit Mining – Also known as open-cast mining, open-cut mining, and strip mining, this type of mining extracts rock and minerals from the earth by their removal from an open pit. The process requires the digging of large open holes as opposed to a small shaft and tunnels used in hard rock mining. Not so often utilized in the 19th century, it is a common practice today, especially with copper and coal. Because this type of mining devastates the landscape, regulations are generally in effect that requires companies to restore the environment when the mining is complete.
Lode Claims – Deposits subject to lode claims include classic veins or lodes having well-defined boundaries. They also include other rock in place bearing valuable minerals and may be broad zones of mineralized rock. Examples include quartz or other veins bearing gold or other metallic minerals and large volume but low grade disseminated metallic deposits. Federal statute limits their size to a maximum of 1,500 feet in length along the vein or lode. Their width is a maximum of 600 feet, 300 feet on either side of the centerline of the vein or lode. The end lines of the lode claim must be parallel to qualify for underground extra-lateral rights. Extra lateral rights involve the rights to minerals that extend at a depth beyond the vertical boundaries of the claim.
Placer Claims – Mineral deposits subject to placer claims include all those deposits not subject to lode claims. Originally, these included only deposits of unconsolidated materials, such as sand and gravel, containing free gold or other minerals. By Congressional acts and judicial interpretations, many nonmetallic bedded or layered deposits, such as gypsum and high calcium limestone, are also considered placer deposits. The maximum size of a placer claim is 20 acres per locator. An association of two locators may locate 40 acres, and three may locate 60 acres, etc. The maximum area of an association placer claim is 160 acres for eight or more persons. The maximum size of a placer claim for corporations is 20 acres per claim. Corporations may not locate association placer claims unless they are in association with other private individuals or other corporations as co-locators.
Mill Sites – A mill site must be located on non-mineral land with its purpose being to either support a lode or placer mining claim operation or, support itself independent of any particular claim. A mill site must include the erection of a mill or reduction works and/or may include other uses reasonably incident to the support of a mining operation. Descriptions of mill sites are by metes and bounds surveys or legal subdivision. The maximum size of a mill site is 5 acres.
Tunnel Sites – A tunnel site is where a tunnel is run to develop a vein or lode. It may also be used for the discovery of unknown veins or lodes. To stake a tunnel site, two stakes are placed up to 3,000 feet apart on the line of the proposed tunnel. Recordation is the same as a lode claim. Some States require additional centerline stakes.
An individual may locate lode claims to cover any or all blind (not known to exist) veins or lodes intersected by the tunnel. The maximum distance these lode claims may exist is 1,500 feet on either side of the centerline of the tunnel. This, in essence, gives the mining claimant the right to prospect an area 3,000 feet wide and 3,000 feet long. Any mining claim located for a blind lode discovered while driving a tunnel relates back in time to the date of the location of the tunnel site.
Federal Lands Open to Mining:
There are federally administered lands in 19 States where you may locate a mining claim or site. These States include Alaska, Arizona, Arkansas, California, Colorado, Florida, Idaho, Louisiana, Mississippi, Montana, Nebraska, Nevada, New Mexico, North Dakota, Oregon, South Dakota, Utah, Washington, and Wyoming.
In these States, the Bureau of Land Management (BLM) manages the surface of public lands and the Forest Service manages the surface of National Forest System lands. The BLM is responsible for the subsurface on both public lands and National Forest System lands. You may prospect and locate claims and sites on lands open to mineral entry. Claims may not be staked in areas closed to mineral entry by a special act of Congress, regulation, or public land order. These areas are withdrawn from the operation of the mining laws. Before mining on any federal land, prospectors would be well advised to check first with the both the Bureau of Land Management and the state before moving forward.