7 A mineral deposit is a naturally occurring mineral accumula tion that may have potential value An ore deposit is a mineral deposit that has been tested and is known to be of sufcient quality to be mined economically Sometimes several metals occur in the same deposit such as lead zinc and copper or silver and gold R esour c es a re concentrations of miner als c oal or other c om modities in such form that the y can be extracted with curr ent t echnology or the e xtr action pot ential is c onsider ed f easible in the futur e R esour c es ma y be kno wn t o e xist or the y ma y be surmised t o e xist based on g eologic e videnc e US coal resources are estimated to be nearly 4 trillion tons enough to pr o vide fuel f or many generations of Americans R eserv es are known identifed resources from which a usable minera l commodity can be technologi cally economically and legally extracted at the time of determination A fall in price for instance can change the character of a deposit from reserve to resource Additionally exploration drilling that further delineates a deposit can add to r eserv es According to the US Energy Information Adminis tration EIA the US has more than 250 billion tons of recoverable coal reserves enough to last more than 300 years at current rates of use W here are resources found Most US mineral resources a re located in the W estern states including Alask a and t he areas with the most promise for ore discoveries ar e primarily within federally managed public lands T he Bureau of Land Management BLM manages 700 million acres of subsurface public land representing as much as 60 percent of the nations hardrock mineral land area however less than half of that area currently is open for mineral exploration and production Coal is present in 38 states and underlies nearly half a million square miles or 13 per cent of the nations land area Coal reserves are split between the E astern and W estern s tates the most important coal deposits in the East are in Appalachia which includes portions of nine states The West contains the Wyodak coalbed which is the nation s leading source of coal and part of the Powder River Basin of Wyoming and Montana In the interior states coal occurs in several basins located from Michigan to Texas RES OUR CES What ar e r eserv es and r esour c es ORE is r ock t h a t c ont ains impor t ant miner als including met als Mining C laims on F eder al Land in the W est BLM US F or est Servic e Mining claim www g eoc ommunicat or g o v