Not sure if you are writing about a paper map or?
The survey lines didn't change and the projection doesn't really matter as long as they didn't use any of the non standard map projections Google uses (they may have see below).
The lines on a map aren't the official survey even though they come from the BLM. The pins on the ground are what matters and those don't change. The BLM can't just survey an unsurveyed area. It takes an Act of Congress with funding to initiate a new survey and there hasn't been one of those since 2002. The BLM can however resurvey to reset lost or missing pins and make projected grids over unsurveyed lands.
If you are in California a
lot of the land there has never had a cadastral survey so the Township, Range and Sections are "projected" by grid as if the land had been surveyed. This has been done poorly in the past in some areas and some projected grids are being replaced. These projected grids over unsurveyed land are theoretical only.
If you located a claim without a real, on the ground, cadastral survey in place you may have relied on a projected survey on a map. I always recommend using metes and bounds descriptions on those claims on unsurveyed lands as well as making a general reference to the projected grid. If you haven't done so you might have some issues with BLM minerals but maintaining your stakes and monuments will give you a leg up over their nonsense. The actual location on the ground legally trumps all the maps and projected surveys. Another reason to clearly mark your location on the ground.
Following the law of location laid down in the 1872 Mining Act is always a good idea. Locators are instructed to use metes and bounds locations when there is no survey. The rule for surveyors prohibits projecting surveys involving property rights that are more than two miles from the nearest physical pin. Beyond that there is no expectation of accuracy.
The BLM has been using a very old PLSS shapefile with a lot of errors and some pretty bad "fixes" for years. They do have the new CadNSDI files that might become the new digital PLSS but those have their own problems. We are investigating those right now but the BLM has been reluctant to share all of those. We are working with them to see if those Cad files will work on our maps. We are also working on making the Survey Field Notes available for download from our maps. A lot goes on behind the scenes to make accurate maps available at Land Matters.
Google projections can not be approved by the standards organizations because they are about 300 feet off and they won't follow any standards. That's fine if you are just using Google Maps or Google Earth and you just want to see what's nearby but measurements are not accurate and other maps won't line up.
If you are using GIS software and using a Google projection like 900973 or 3867 or one of the other 5 or so projections they hop between you will probably need to add "reaspect=false" to your call code - that should move the lines over about 270 feet and get you within 30 feet of the one you are used to. If you don't have to use a Google projection avoid them if you want any accuracy.
That may seem like a lot of information but you asked a pretty complex question. I hope the information helps. If you have more questions feel free to ask. We've got a real life cadastral surveyor here on the TNet prospecting forum and maybe he will add some inside information for you.
Heavy Pans
