# Relationship history for MSHA mine 4603143

Current hierarchy: **Virginia Conservation Legacy Fund (VCLF) → ERP Environmental Fund Inc. → Big Mountain Preparation Plant**

- Valid-time bounds: inclusive, date granularity
- Null end: open-ended in the upstream history row; not independent proof of present control
- Transaction-time observation: 2026-10-13T11:19:05.459773+00:00

## Valid-time edges

- **operator_operates_mine:** Big Mountain Coals Inc → Big Mountain Preparation Plant; 1950-01-01 to 1984-02-26; source msha-controller-operator-history
- **controller_controls_mine:** Armco Inc → Big Mountain Preparation Plant; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Armco Inc → Big Mountain Coals Inc; 1950-01-01 to 1984-02-26; source msha-controller-operator-history
- **operator_operates_mine:** Pine Ridge Coal Company → Big Mountain Preparation Plant; 1984-02-27 to 1998-05-18; source msha-controller-operator-history
- **controller_controls_mine:** Hanson PLC → Big Mountain Preparation Plant; 1984-02-27 to 1998-05-18; source msha-controller-operator-history
- **controller_controls_operator:** Hanson PLC → Pine Ridge Coal Company; 1984-02-27 to 1998-05-18; source msha-controller-operator-history
- **operator_operates_mine:** Pine Ridge Coal Company LLC → Big Mountain Preparation Plant; 1998-05-19 to 2016-01-07; source msha-controller-operator-history
- **controller_controls_mine:** Peabody Energy Corporation → Big Mountain Preparation Plant; 1998-05-19 to 2007-10-30; source msha-controller-operator-history
- **controller_controls_operator:** Peabody Energy Corporation → Pine Ridge Coal Company LLC; 1998-05-19 to 2007-10-30; source msha-controller-operator-history
- **controller_controls_mine:** Patriot Coal Corporation → Big Mountain Preparation Plant; 2007-10-31 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Patriot Coal Corporation → Pine Ridge Coal Company LLC; 2007-10-31 to 2016-01-07; source msha-controller-operator-history
- **controller_controls_mine:** Virginia Conservation Legacy Fund (VCLF) → Big Mountain Preparation Plant; 2015-10-28 to 2017-01-25; source msha-controller-operator-history
- **operator_operates_mine:** ERP Environmental Fund Inc. → Big Mountain Preparation Plant; 2016-01-08 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Virginia Conservation Legacy Fund (VCLF) → ERP Environmental Fund Inc.; 2016-01-08 to 2017-01-25; source msha-controller-operator-history
- **controller_controls_mine:** Kissito Healthcare Inc → Big Mountain Preparation Plant; 2017-01-26 to 2018-12-31; source msha-controller-operator-history
- **controller_controls_operator:** Kissito Healthcare Inc → ERP Environmental Fund Inc.; 2017-01-26 to 2018-12-31; source msha-controller-operator-history
- **controller_controls_mine:** Virginia Conservation Legacy Fund (VCLF) → Big Mountain Preparation Plant; 2019-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Virginia Conservation Legacy Fund (VCLF) → ERP Environmental Fund Inc.; 2019-01-01 to current/open; source msha-controller-operator-history