# Relationship history for MSHA mine 4605906

Current hierarchy: **Patriot Coal Corporation → Arch Of West Virginia → Underground Mine #1**

- 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:** Quaker State Corp → Underground Mine #1; 1950-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Shrewsbury Coal Company → Underground Mine #1; 1978-10-01 to 1992-12-31; source msha-controller-operator-history
- **controller_controls_operator:** Quaker State Corp → Shrewsbury Coal Company; 1978-10-01 to 1992-12-31; source msha-controller-operator-history
- **controller_controls_mine:** Ashland Inc et al → Underground Mine #1; 1987-05-19 to 2005-12-31; source msha-controller-operator-history
- **operator_operates_mine:** Arch Of West Virginia → Underground Mine #1; 1993-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Ashland Inc et al → Arch Of West Virginia; 1993-01-01 to 2005-12-31; source msha-controller-operator-history
- **controller_controls_mine:** Magnum Coal Company → Underground Mine #1; 2006-01-01 to 2008-07-22; source msha-controller-operator-history
- **controller_controls_operator:** Magnum Coal Company → Arch Of West Virginia; 2006-01-01 to 2008-07-22; source msha-controller-operator-history
- **controller_controls_mine:** Patriot Coal Corporation → Underground Mine #1; 2008-07-23 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Patriot Coal Corporation → Arch Of West Virginia; 2008-07-23 to current/open; source msha-controller-operator-history