30 CFR § 48.2
For the purposes of this subpart A--
(a)(1) Miner means, for purposes of § § 48.3 through 48.10 of this subpart A, any person working in an underground mine and who is engaged in the extraction and production process, or engaged in shaft or slope construction, or who is regularly exposed to mine hazards, or who is a maintenance or service worker employed by the operator or a maintenance or service worker contracted by the operator to work at the mine for frequent or extended periods. This definition shall include the operator if the operator works underground on a continuing, even if irregular basis. Short-term, specialized contract workers, such as drillers and blasters, who are engaged in the extraction and production process or engaged in shaft or slope construction and who have received training under § 48.6 (Experienced miner training) of this subpart A may, in lieu of subsequent training under that section for each new employment, receive training under § 48.11 (Hazard training) of this subpart A. This definition does not include:
(i) Workers under subpart C of this part 48, engaged in the construction of major additions to an existing mine which requires the mine to cease operations;
(2) Miner means, for purposes of § 48.11 (Hazard training) of this subpart A, any person working in an underground mine, including any delivery, office, or scientific worker or occasional, short-term maintenance or service worker contracted by the operator, and any student engaged in academic projects involving his or her extended presence at the mine. This definition excludes persons covered under paragraph (a)(1) of this section and subpart C of this part.
(b) Experienced miner means:
(1) A miner who has completed MSHA-approved new miner training for underground miners or training acceptable to MSHA from a State agency and who has had at least 12 months of underground mining experience; or
(2) A supervisor who is certified under an MSHA-approved State certification program and who is employed as an underground supervisor on October 6, 1998; or
(3) An experienced underground miner on February 3, 1999.
(4)(i) A person employed as an underground shaft or slope construction worker on June 28, 2006; or
(ii) A person who has six months of underground shaft or slope experience within 24 months before June 28, 2006.
For more information : See MSHA's Program Policy Manual