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Colorado Prospector - Gem and mineral prospecting and mining forums _ Prospectors and Rockhounding Field Work _ Technical mining claim question

Posted by: Coalbunny Oct 21 2010, 09:09 PM

Is there a maximum depth for mining claims? If so, where does it start and where does it end?
In another thread I heard something about 2,000' depth, but that confuses me as some mines go past that. In such a case would it start at the claim surface or the terrain surface? The Kennicott open pit mine over by Magna Utah is a good example. Or is it from the last workings? Please explain.

Posted by: Persistence Oct 21 2010, 09:59 PM

I'm fairly sure there is no depth limitation, only surface area limitations. Other words, you can go straight down, so long as you are within the surface borders. I'm no expert, so YMMV. I think this has been challenged in oil drilling, where a company will drill at an angle to hit the same crude oil pocket.

Posted by: Coalbunny Oct 21 2010, 11:32 PM

Nah, similar general industry (mineral resource recovery), but two separate law groups (mining law vs. petroleum law).

Posted by: ColoradoProspector Oct 24 2010, 09:54 AM

Good question you posed Coalbunny, not sure if I know the right answer but I do have some thoughts on it.
First lets look at if from claim types, if it's a lode claim then the claim is orientated to the dike/ore body discovered where as a placer claim is claiming the "aluvial deposits" within that claim which would be orientated on those deposits and fantails away from their "lode" deposits where formed.
Depths I think are generally understood as everything straight down but it's not the case in many mining districts, Gilpin and Teller counties come to mind where the claims often overlapped at different depths.
Again though just looking at lode types vs placer, depths of course will vary widely but the placer only contains the "aluvial" materials where as lode claims would in fact orientate on a dike or ore body at what ever angle of declination and direction it went. Placers can be odd shapes that orientate where nature left the placers, lodes are always rectangles at a specified size centered on the vien/ore body.

In Gilpin and Teller counties as with many others there were depth limits on claims which I believe comes from the old mining days when the seperate mining districst set their own rules/laws and policed their own. Molly Kathleen in Cripple Creek/Victor districts (the first woman to file a mining claim in Colorado), made more money on the other 7 mines (below and along her mine's shaft), that used her mine shaft to extract their ore than she made from her own mine.
So if the old districts incorperated depth limits back in the 1800's then today they would still stand and may not be consistent or the same from one district to another. Thats some really old information and would be hard to track down to the original setting when started I bet.
Some mining districts may not have had any depth limits at all.

It also makes you wonder about how they extended and or turned the next claims filed once the limits where reached of the original lode claim boundries. File another claim attatched at the direction they thought the vein/ore body kept heading? The guy that made that call had to be right or the big guys in the office would be urked!

Petroleum however is a whole different world as Coalbunny said with different laws as "leasable" minerals rather than "locatables". The leasable minerals (oil, coal, gas, sand, gravel) are run under additional laws and the government does in fact claim ownership on those so they are "leased" by private companies to extract them. Royalties must be paid based on production plus the yearly fees etc.

Interesting question though, I wonder how many districts had no depth limits vs how many that did?

CP

Posted by: old gold miner Dec 17 2010, 01:42 PM

There are two (2) types of mining claims, Lode & Placer. On Lode claims, so long as a vein “apex’s” (crops out at the surface or peaks at depth) inside the boundary of the claim, there is no limit to the depth you can follow it downward. At depth you can also follow the vein outside the vertical surface boundary of the claim. Which is referred to as “extralateral” rights. Very few lode veins are truly vertical. Most tilt at an angle (along their dip & strike). Consequently, a vein may apex at the surface inside the boundary of a claim. But, at depth the vein may actually runs through the vertical sideline boundary at an angle. Thus, early mining litigation established the extralateral rights doctrine. So that mine owners could continue to follow and mine such veins at depth.

Placer claims are generally limited to the depth of alluvial gravel that carries values.

http://www.blm.gov/ca/st/en/info/iac/faqmc.html