# Relationship history for MSHA mine 4608548

Current hierarchy: **Patriot Coal Corporation → Pine Ridge Coal Company → Williams Mountain Surface Mine**

- 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

- **controller_controls_mine:** Ballard Ralph L Iii-Phillip R Cooper Et Al → Williams Mountain Surface Mine; 1994-10-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Asset Management Group Inc → Williams Mountain Surface Mine; 1996-02-01 to 2001-06-24; source msha-controller-operator-history
- **controller_controls_operator:** Ballard Ralph L Iii-Phillip R Cooper Et Al → Asset Management Group Inc; 1996-02-01 to 2001-06-24; source msha-controller-operator-history
- **controller_controls_mine:** Peabody Energy Corporation → Williams Mountain Surface Mine; 1998-05-19 to 2007-10-30; source msha-controller-operator-history
- **operator_operates_mine:** Pine Ridge Coal Company → Williams Mountain Surface Mine; 2001-06-25 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Peabody Energy Corporation → Pine Ridge Coal Company; 2001-06-25 to 2007-10-30; source msha-controller-operator-history
- **controller_controls_mine:** Patriot Coal Corporation → Williams Mountain Surface Mine; 2007-10-31 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Patriot Coal Corporation → Pine Ridge Coal Company; 2007-10-31 to current/open; source msha-controller-operator-history