# Relationship history for MSHA mine 4406723

Current hierarchy: **Amvest Corporation → Glamorgan 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: 2026-10-17T05:35:58.500035+00:00

## Valid-time edges

- **controller_controls_mine:** Amvest Corporation → Mine No 1; 1976-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Rick A  Matney  et al → Mine No 1; 1983-01-03 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** O M Vicars Coal Company → Mine No 1; 1992-11-01 to 1998-08-31; source msha-controller-operator-history
- **controller_controls_mine:** Amvest Corporation → Mine No 1; 1992-11-01 to 1998-08-31; source msha-controller-operator-history
- **controller_controls_operator:** Amvest Corporation → O M Vicars Coal Company; 1992-11-01 to 1998-08-31; source msha-controller-operator-history
- **operator_operates_mine:** Bristol Coal Corp → Mine No 1; 1998-09-01 to 1999-05-31; source msha-controller-operator-history
- **controller_controls_operator:** Rick A  Matney  et al → Bristol Coal Corp; 1998-09-01 to 1999-05-31; source msha-controller-operator-history
- **controller_controls_operator:** Hank K  Matney  et al → Bristol Coal Corp; 1998-09-01 to 1999-05-31; source msha-controller-operator-history
- **controller_controls_operator:** Fred D  Matney  et al → Bristol Coal Corp; 1998-09-01 to 1999-05-31; source msha-controller-operator-history
- **operator_operates_mine:** Glamorgan Coal Company → Mine No 1; 1999-06-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Amvest Corporation → Glamorgan Coal Company; 1999-06-01 to current/open; source msha-controller-operator-history