The devil is in the details Goldwasher.
Try using the
Land Matters California
Land Status Map and look closer. The government provided Land Management files we use to build that layer aren't super accurate but you will notice if you zoom in that the river itself is not shown as within the BLM land. That should tip you off that you need to look closer.
The first step to looking closer is to turn on the Master Title Plat (MTP) layer and click to download the MTP for 11N 9E. These are the status maps that the Federal government uses to layout the status of all the lands they manage and to show the patents for the lands they don't manage. These maps can be hard to read because they don't show many of the features of the land that we normally use to find our bearings.
Look at the area in Section 21 to get a simplified idea of the issue here. See that dotted line? Notice that the dotted line is west of the solid line? The solid line is the private boundary of the river course and the dotted line is the extent of the BLM land management. Just like the map when you zoom in the BLM land
does not include the river.
See that area to the East of the dotted BLM line? It's marked with nothing but the number 4. That number 4 is the Patent number for that private land (very old patent). You can look up California Patent 4 at the
General Land Office (GLO). That Patent will describe the exact area of the patent in metes and bounds. Now look at the BLM portion west of the river. See how the arrow indicates it's CACA 25889 P4 Recon US All Min? That is the pointer to the BLM Serial number that describes how P4 is part 4 of the reconveyance of that portion of the Patented land back to the United States. Look up that CACA 25889 number in the Serial Register page at the LR2000 and you will find some of the details and restrictions of that transaction. More details of that transaction will be found at the GLO under the CDI and Historical Index.
As you can see the Feds don't make this easy. If you think that was tough to understand try looking at Section 10 on the MTP where it looks like the whole section is hunky dory go prospect your azz off land on the overall Land Management layer. Once you work your way through understanding whats going on there give me a call. I could use some people that can research land status on that level.
That GLO/LR2000 back and forth thing can be a nightmare even for experienced land status researchers. We are close to providing Patents, CDI, Surveys and Historical Indexes with a click on the Land Matters Maps to help save you the time and frustration searching multiple government data sites. That's high on our long list of new research tools but we're going to need more than a little time to get that done. We all have to make a living in the meantime just like you.
Now that you have met the devil I will tell you that I see a few very small areas that
might be legally prospected - if you can legally get there. That
might be is in those devilish details. Those details really don't leave room for broad statements like "you can metal detect above the bridge" or "you can't metal detect west of 49". It's really just not that simple.
Heavy Pans