I have to correct a couple of things that has been said.
A federal mining claim, on BLM land takes a couple of things. First, find out if its claimable (meaning, nobody else has it claimed, it is open for claim and if there are minerals there).
Second, you do some of this by going to the local BLM office (assuming it is on BLM land). Check for things like withdrawals, etc. ONE BIG POINT, here. Some lands are withdrawn from mining everything EXCEPT precious metals. Follow up on any "special regulations" by reading
it carefully. Several years ago, we got a withdrawn area in Alaska opened back up, by reading the fine print, and then bringing it to the BLM's
attention. There are many good mines there now.
Third - when you file for a claim, make sure you do your monuments and you know where you are - exactly. We have had people file over us,
more than once. One of the "gentlemen" who filed over our claim met us at the mine and proceeded to try to throw us off. He felt kind of dumb when (a) he didn't realize he was facing west (he'd said north), and (b) he went to the local BLM office and found out our claim pre-dated his by more than 15 years. Know where you are. (and have a "discovery") - by the way, someone will tear down your monuments on a regular basis.
Now - you do NOT have to do assessment work and pay an annual fee. You do one or the other. If you have 10 or less claims, you can file
a small miners waiver. (but, if you do, you HAVE to do your assessment work).
Every year, if you file the small miners waiver, you send that to the BLM by 8/31 and then you have to file your assessment work by December 31st. (depending on what day of the week that falls on). Then, you send a copy of that with a copy of your waiver to the BLM and they charge
$10.00 per claim to the BLM, and a copy to the county in which the claim is (to the recorders office). The recorders office charges for recording
it.
If you have more than 10 claims, then you have to pay an assessment fee - this year was $145.00 each claim.
You can detect on BLM land - the only time you cannot is if it is specifically withdrawn for some reason, and you cannot metal detect graves, historical areas and stuff like that.
If you have a mining claim, you can keep people away, legally, only from your active mining area and where your equipment is. However, if
you metal detect on someone elses claim without permission, and they file charges against you - it can get expensive for you, really fast. It
is a class 3 felony in most states, a class 2 in some others. (mineral trespass).
Also - a lode claim trumps a placer. (technically). A lode claim follows a vein, for X number of feet. If you have a placer over a lode, the area
away from the lode is free territory. The area directly over the lode is NOT up for grabs. (so says the courts in almost every state where it has
been brought to). And, a placer is done in sections. (like the SW1/4 of the SW1/4 section 8, township XX, Range XX) in 20, 40, 60, 80 or 160
acres (which is an "association claim").
Beth