If you have researched that BLM land is ok to metal detect on, then unless it it posted with signs then go ahead and do it. We have areas that charge to park your vehicle, for the cross country skiers and hikers, so check and see if you need a vehicle pass sticker. Then head out. Bet you didn't think of that huh? That's why we say to research on your computer. Each State may be different for BLM. Some may require vehicle parking pass, some may not, some area's may have protected lands in certain area's, some may not. Your computer is your best answers to your questions. Good Luck.