Hi Starsplitter, Jeff in PA, and all my TH'ing Friends
Searching on Government land is difficult but not an impossible thing to accomplish. although Jeff may be partially correct I don't believe many of the folks out there in the Government or with tons of money will give anyone a 'Get out of jail' pass. I have searched many US Military bases across the US and it all comes down to being smart and spending time with the correct offices. If you find a US Military base that you would like to check out you will have to visit the person in charge of the 'Public Relations Office'. You will have to visit them during their office hours which in the Military is normally for 8 am until 3 pm. Do not go in with an 'I deserve to search anywhere' attitude as they will tell you no. You have to present yourself in a light that is on par with going in for a job interview. You have to impress the Officer or Noncommissioned Officer that what you are doing is to recover items that were lost, that you will cover carefully and completely every one of your holes (I hope you read this Ron), and that if you do find anything of Historic Interest you will turn this in to the Public Relations Office. One of the US Military bases required my TH'ing buddy and myself to sign a 'Release of Liability' due to the fact that this installation used and still uses lots of live munitions, including air dropped bombs, explosives, and munitions of every description. Before you even get started you have to be aware that there are things in the ground that will kill or injure you and guess what the US Military will not be held responsible for your injuries or recovery expenses.
As for searching in US National Parks; you can almost 100% of the time FORGET ABOUT IT. I have also read about those that claim to have gotten written approvals to search a certain beach within a US National Park, but my experience has always been NEGATIVE when it comes to dealing with the US National Park service. I find it to be a waste of time to explain anything to the head set mentality that is shown to the public. Please allow me to provide you with one of my experiences dealing with the US Park Service: While on a relocation move from Reno Nevada to New Orleans LA in April 1989 we decided to drive and see the many Natural and Historic sites along the way. We had mapped our route so we could take in the many neat sites and one we decided on was the Great Petrified Forest, as we entered the front gate we were asked if we had any rocks or fossils and Metal Detectors. I explained that we were traveling cross county and that yes we had some of all of the above. We were requested to pull over and that they would have to inspect our vehicle. When we opened our trunk they were horrified at the amount of fossils, rocks and my metal detector. We were then told or should I say we were read the riot act, basically we were being warned that we could not remove or disturb any rocks or formations within the park. I informed the park ranger that we were not there to do any of those activities and that we only wished to visit the park and see the beauty of the 'Rock forest'. They then jumped on me for having a metal detector in my vehicle and that just bringing it into a US National Park was illegal. I was also informed that I would not be allowed to use it and that if I was found in the park using my detector I would be arrested, my detector would be seized, I would go to jail for a while, I would also be fined several thousand dollars. I again explained that I was traveling to New Orleans, I was aware of the rules against using a detector within any US National Park and that I had no intention nor the time to use a detector while visiting their park. They had to discuss this several times with several different rangers and then they decided to call in their boss. After again explaining what we were doing and what our plans were regarding our visit to the park a decision was made (believe it or not) first the park service provided plastic baggies for all our rocks and fossils, which was fine with me except that I had two very large pieces of petrified tree that I found in NV that they did not have a bag large enough for so they put stickers on them and said that would be the best they could do, second I would need to bag up all my battery packs for my detector, again no problem as I was not planning to use it in the park anyway. We were told that we would also need to exit from the same side of the park as we had entered, our plans were to go right through the park as it was on our route and coming back would add about an hour to our time, they said that they would call ahead and inform the other exit that we would be exiting at their location and provided them with a list of what was bagged and we were then allowed to enter the park to enjoy the remaining shortened visit as our timeline was short and this had taken all of an hour to finalize. We took pictures of rock formation and rock trees and the park itself was wonderful, just had to wonder about the mental cases in charge of the place.
Now I do want to touch on the way things are done in Germany as I was there in 1973 - 1979 and used my detector to find and recover many nice items. The main thing most TH'ers fail to realize is that not all land is free or available to search. One of the things that is different about Germany is that they have protected any land that was developed, fortified, built on by the Romans. There are ways around this but of course there is a catch; first you have to go to a University to locate the office that is doing research in an area that you want to TH; then you have to become educated in how they intend to search the area. Normally the TH'er is allowed to locate items but not recover; the archaeologist takes care of the recovery. If what is recovered is not Roman or Early Germanic, or what ever era they were looking for the item is given to the TH'er (unless it is of historic value). The university holds all the trump cards and the TH'er is merely an on looker. Here again if you spend time with one university you will eventually be given more ability to search and recover but you will still need to present your finds to the person in charge of the search team, and if it is important you will be required to turn over your finds. So much history is lost because people find it illegally and keep it for themselves that it may get to a point that possession of a detector may be out lawed. As I was in the US Army during my stay in Germany I searched many US Bases and located a lot of WWI and WWII items, including my one and only 40 pound bomb. I did search a few private homes and properties but not speaking German hindered me. My suggestion if you want to search in any foreign county either learn the language, have an interpretor, or be ready to be told to leave or be arrested. There are areas in France and Germany (and elsewere) that had so many battles that it is still unsafe to enter, I would avoid these areas unless you really want to take your life into your own hands. I was lucky with my bomb but it sure could have gone bad. My bomb was part of a 500 pound cluster bomb that was dropped in June or July 1944 on a group of a dozen Panzer tanks that were caught out in the open. They were attempting to take cover in a nearby wooded area but were hit with 'White Phosphor' and disabled. The story was provided to me from an eye witness who was a mere child of eight or nine, he stated to me that to that day (September 24th 1978) he could still hear the screams of the tankers as they attempted to exit their burning tanks. All the tanks were destroyed and all the tankers were killed.
I plan to one day visit both Germany and England to TH for relics and hope that all the laws are made a bit easier to deal with as England has done with their law.
How soon the US will follow is anyone's guess. I do like what occurred at the Manassas Battle and the Little Big Horn Battle Parks. The US Park Service needed to pave an area of the Manassas Park next to the 'Stone House' (those that have visited the park know where the Stone House is and where the parking lot was put). The US Park Service did not have the funds to hire archaeologist to search the entire area so they invited TH'ers by lottery to locate targets (No Digging of anything located) and had archaeologist recover the items.
The Battle of the Little Big Horn has had a book written about it and the items recovered, but suffice it to say they did the same as for inviting TH'ers in to locate targets and archaeologists to recover. This is the type of baby steps it will take to open all US Government lands for TH'ing, but we are years away from this happening.
I will continue to seek out private property and recover my two or three Civil War relics and be content with that.
Be Safe and have fun in all you do, but do right always!
Dave Mork
'Digger-Dave'
THing4CSA
PS: Remember; Don't leave it in the ground!
GEE WHIZ. 
