# Relationship history for MSHA mine 4406707

Current hierarchy: **Amvest Corporation → Mountain Trail Coal Company → Mine No 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:** Stephen D  Halsey et al → Mine No 1; 1986-12-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Wolverine Coal Company Inc → Mine No 1; 1992-08-01 to 1994-02-28; source msha-controller-operator-history
- **controller_controls_operator:** Stephen D  Halsey et al → Wolverine Coal Company Inc; 1992-08-01 to 1994-02-28; source msha-controller-operator-history
- **controller_controls_operator:** Carl A  Hamilton et al → Wolverine Coal Company Inc; 1992-08-01 to 1994-02-28; source msha-controller-operator-history
- **operator_operates_mine:** Mountain Trail Coal Company → Mine No 1; 1994-03-01 to 1994-05-23; source msha-controller-operator-history
- **controller_controls_mine:** Amvest Corporation → Mine No 1; 1994-03-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Amvest Corporation → Mountain Trail Coal Company; 1994-03-01 to 1994-05-23; source msha-controller-operator-history
- **controller_controls_mine:** Roberts Sandra → Mine No 1; 1994-05-11 to 1994-10-24; source msha-controller-operator-history
- **operator_operates_mine:** Mountain View Mining Inc → Mine No 1; 1994-05-24 to 1994-10-24; source msha-controller-operator-history
- **controller_controls_operator:** Roberts Sandra → Mountain View Mining Inc; 1994-05-24 to 1994-10-24; source msha-controller-operator-history
- **operator_operates_mine:** Mountain Trail Coal Company → Mine No 1; 1994-10-25 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Amvest Corporation → Mountain Trail Coal Company; 1994-10-25 to current/open; source msha-controller-operator-history