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Hi Ya'll!  I'm planning my Big Montana Adventure this summer and looking at Montana Cadastral and Google Earth for potential detecting spots.  I'm seeing lots of interesting tailing and dredge piles on Google Earth in some of the former placer and pit mining areas (now BLM land).  But then when I read the history of the particular mining operation I see that most of them have been gone over twice-once with a rock crusher/arastra type outfit, then again with cyanide or mercury extraction.  So is tailing pile material still worth going over with a detector if it's already been worked over with the chemical extraction methods like cyanide?  Or, as I suspect, would there be nothing left big enough to be found by a detector?  Would it even be safe to detect in these areas, or has the cyanide/mercury leached away decades ago?  Please excuse my ignorance as I am a newbie to this gold mining stuff. Thanks guys!

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Better states for detecting IMO--if you are going there and are detecting as a side venture then that's different.

I would pick other states such as CA, AZ, NV if Montana isn't proprietary.

It is a beautiful state tho--i used to have a home in Ennis---south of Bozeman near Alder...

But I was addicted to ETOH back then instead of AU :wink:

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Strange.  I would not expect there to be much cyanide treatment with dredge tailings.   But what do I know.  Definitely check to see if the mines nearby had "FreeMilling" gold and you should be good.  Also look for "High Grade Ore".  Or just look at the tailings to spy free gold.  I have a recent post where I ran across an old hard rock mine with quartz tailings and there was some obvious gold visible.  Later we crushed pieces and there was gold inside.  (and a good amount of it)  You need a good detector for the really small stuff.  Sounds like you're going big :)  

Also, in case you haven't already done so, do a search on detecting mine tailings.  You will get some very good articles that detail how to attack those dredge piles.  

Other than that ...  what Paul said :tongue:

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Tailings from a heap leaching/cyanide recovery operation should not have any detectable gold if any at all.  A mine dump may have some gold as Andyy suggests.  Dredge tailings maybe have nuggets if the area they dredged was known for nuggets rather than fine gold.  Most of the dredge piles in Montana are now sitting on private land because the original claims were patented.  I am not sure where one could get access to dredge piles.

If you don't already have this book get it.  It shows all the places in Montana that were placer mined:

http://www.mbmg.mtech.edu/mbmgcat/public/ListCitation.asp?pub_id=11597&

I would think your best bet would be to check for open land on the streams indicated in the book.  Also check our the Libby Creek free panning area south of Libby.  The Northeast Montana Prospecting Club has claims in that area.  Cost to join $50 or $75.

http://www.nwmtgoldprospectors.com

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23 hours ago, hawkeye said:

Tailings from a heap leaching/cyanide recovery operation should not have any detectable gold if any at all.  A mine dump may have some gold as Andyy suggests.  Dredge tailings maybe have nuggets if the area they dredged was known for nuggets rather than fine gold. 

Very good advice hawkeye. Tailings from a cyanide operation would very much likely have absolutely no detectable gold at all, & like you say, if any gold at all. Your best bet MontAmmie would be to get to the area or dumps prior to the material being worked over again & put through the cyanide process. Even then the tailings may be just a fine crushing that was washed over mercury covered copper plates after going through the stampers or ball mill & still may have no detectable gold. Maybe a speck or two for a high frequency VLF to pick up on or tiny stone/quartz fragments that washed on over the plates escaping the mercury that has tiny gold in the stone. You really need to hit the ore stockpile area, prior to the final crushing in either stamper or ball mill which reduces the ore to a powder.

I don't know about the mines in the area that you are speaking of but I know that many of the hard rock mines in the Coromandel Peninsular region of New Zealand really struggled & even went under in the early years due to not being able to recover profitable returns. Despite the fact that they knew through laboratory assay that they were losing more gold & silver in their tailings than they were saving. This was due to complex ores that had high sulphides & other impurities that through the then only known mercury recovery process the mercury was being coated & sickened by these sulphides & impurities. Allowing the fine gold & silver particles no contact with the mercury & hence skipping on & over the plates & into the tailings waste dump, or in most cases...straight in to a river or stream to be washed away. Must have been hugely frustrating for them, but there just wasn't a process at that time, on a large commercial scale, to get a better recovery that would have made the mines profitable. Some of them realising this stockpiled there waste in the event that a process would come about to recover the gold & silver they knew was in their waste pile.This eventually happened & in 1889 came the breakthrough. The cyanide process was, in a world first, successfully trialled on a commercial scale by New Zealand Crown Mines at Karangahake. The result was that instead of recovering just  45% of the gold & virtually none of the silver, they were recovering 90% of the gold & 50% of the silver. The system was adopted by many other companies on the peninsular & allowed for low grade deposits to be now worked at a profit. Happy days were here again.  Oppsss...sorry, got a bit carried away. :rolleyes:

Best of luck out there

JW :smile:   

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On 2/6/2018 at 7:23 PM, vanursepaul said:

Better states for detecting IMO--if you are going there and are detecting as a side venture then that's different.

I would pick other states such as CA, AZ, NV if Montana isn't proprietary.

It is a beautiful state tho--i used to have a home in Ennis---south of Bozeman near Alder...

But I was addicted to ETOH back then instead of AU :wink:

Sorry, I haven't replied to ya'll.  I didn't get any notifications that anyone had responded.  So anyway, yes, Van, Montana has something more precious than gold....my 5 year old grandson in Bozeman.  The prospecting is just something to do after he gets bored with us.  And it looks like Montana does still have a few good areas left that are not locked up with placer claims.

Hawkeye-From looking at Montana Cadastral, it seems that most of the original mine areas are still owned, but a lot of the tailing piles are not.  It looks like they had to put their mills wherever they could find a flat spot, and often that was quite a few hundred yards from the mine itself.

Andy-From reading the mining reports it looks like they used cyanide on anything that was accessible and suspected to have had a speck of gold left in it.  The mining interests controlled everything and did pretty much whatever they pleased.

JW- Looking at an old mining report from 1950-something,  I have found a huge pile of hand-sorted material just sitting there on public land!  It looks like it was abandoned at the beginning of WW1 and then forgotten.  Now, granted, it is on the side of a remote mountain, but I'm going to see if we can get the ATV up there.

The main areas that I'm looking at are valleys near gold-producing areas, which might have some detectable nuggets, but weren't worked back in the day due to lack of water.  Do ya'll think this is a good strategy?

I'll be sure and let you guys know how it goes.  When I can.  We won't have internet (getting an emergency satellite beacon) for most of the summer.  I'm going to print out all this info.  I'll probably have tons more questions when I actually get back up there and see it.  Thanks so much, y'all!

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Just come on out and ENJOY the area like you planned.  Do your research and I'm sure you'll find some areas to scratch around in?  I'm new and a rookie so can't recommend any areas near Bozeman but you'll find some. Might learn to use the claim maps here to help locate area claims?   Good luck!!!    http://www.mylandmatters.org/Maps/Mining.html 

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On 2/13/2018 at 12:43 PM, oneguy said:

Just come on out and ENJOY the area like you planned.  Do your research and I'm sure you'll find some areas to scratch around in?  I'm new and a rookie so can't recommend any areas near Bozeman but you'll find some. Might learn to use the claim maps here to help locate area claims?   Good luck!!!    http://www.mylandmatters.org/Maps/Mining.html 

Oh, I will!  We love Montana.  My husband spent about 20 years there (Choteau and Bozeman), so he knows the area well.  I've been keeping the Landmatters and Cadastral maps open all the time while I read old mining reports. Thanks!

I have another question for you guys.  Does placer gold replenish itself?  I know it washes down from the quartz veins in and on the mountains after water erodes it out.  My guess is yes, it does, but probably would take hundreds of years to accumulate in any appreciable amounts.  Thanks ya'll!

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1 hour ago, MontAmmie said:

Oh, I will!  We love Montana.  My husband spent about 20 years there (Choteau and Bozeman), so he knows the area well.  I've been keeping the Landmatters and Cadastral maps open all the time while I read old mining reports. Thanks!

I have another question for you guys.  Does placer gold replenish itself?  I know it washes down from the quartz veins in and on the mountains after water erodes it out.  My guess is yes, it does, but probably would take hundreds of years to accumulate in any appreciable amounts.  Thanks ya'll!

Not familiar with gold "on the other side of the hill" (continental divide), I'm on the west side of the hill.  There's been lots of gold scratching all over the west side like around Helena area, south to Butte, Dillon, and also further west.  I'm sure your hubby knows of some spots or someone that does.  Last spring we had quite the runoff so most the waterways got stirred up with new gold, some old buried with over burden, etc. but definitely things got re-arranged?  Could be good or bad depending.  You guys enjoy..........

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Part of this problem is that a lot of different things get called "tailings" by prospectors and some are worth detecting and others not.

True tailings from a cyanide plant are crushed to be like fine beach sand, usually tan colored and will have no gold that can be found with a detector.

Mine "tailings" such as broken rock that is the waste from the workings of an underground hard rock mine (normally dumped out near portals and shafts) are not crushed, they will have all sizes of rock from small sand to boulders. These can be very worthwhile, I've found some nice gold in them, it just depends on the mine and the type of gold they found. Some mines only produce very fine dust sized gold, while others can produce coarser, chunkier gold that is easily detected.

Placer "tailings" are the materials that have been run through the sluice of a gravel mine. They may or may not have some nice gold depending on the type of sluice they ran and how much gold-quartz was in the gravel.

I made my first trip to Montana this last fall.......

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