Also, LR2000 only breaks down to 1/4 section, any further have to contact them to drill deeper, to see where exactly in that 1/4 section it is. ie., a 20 acre claim in the 160 acre 1/4 section. The bright side is most folks at the claims division in the BLM state offices are very helpful with the information.
Also, here in Oregon, (your state and mileage may vary), corner posts are not required if the claim is located by "legal subdivision", meaning that if it follows section line breakdowns, even down to 5 acre plots, no corner markers are required. The claim my partner and I have is 40 acres, and follws legal subdivision lines, so we didn't have to put up corner markers on it, even though is stair steps on the map. Just had to sign the claim with the MC # & name and post our location/point of discovery.