# Relationship history for MSHA mine 4607684

Current hierarchy: **Core Natural Resources Inc → Mingo Logan Coal Company → Coalburg No 6**

- 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:** Ashland Inc et al → Coalburg No 6; 1977-05-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Allen T  Workman Jr → Coalburg No 6; 1986-08-25 to 1992-03-31; source msha-controller-operator-history
- **operator_operates_mine:** Sharples Coal Corp → Coalburg No 6; 1989-02-01 to 1992-03-31; source msha-controller-operator-history
- **controller_controls_operator:** Allen T  Workman Jr → Sharples Coal Corp; 1989-02-01 to 1992-03-31; source msha-controller-operator-history
- **controller_controls_mine:** Ashland Inc et al → Coalburg No 6; 1990-01-24 to 1996-06-30; source msha-controller-operator-history
- **operator_operates_mine:** Hobet Mining Inc → Coalburg No 6; 1992-04-01 to 2006-02-14; source msha-controller-operator-history
- **controller_controls_operator:** Ashland Inc et al → Hobet Mining Inc; 1992-04-01 to 2006-02-14; source msha-controller-operator-history
- **controller_controls_mine:** Arch Resources Inc → Coalburg No 6; 1997-07-01 to 2025-01-13; source msha-controller-operator-history
- **operator_operates_mine:** Mingo Logan Coal Company → Coalburg No 6; 2006-02-15 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Ashland Inc et al → Mingo Logan Coal Company; 2006-02-15 to 1996-06-30; source msha-controller-operator-history
- **controller_controls_operator:** Arch Resources Inc → Mingo Logan Coal Company; 2006-02-15 to 2025-01-13; source msha-controller-operator-history
- **controller_controls_mine:** Core Natural Resources Inc → Coalburg No 6; 2025-01-14 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Core Natural Resources Inc → Mingo Logan Coal Company; 2025-01-14 to current/open; source msha-controller-operator-history