# Relationship history for MSHA mine 4404481

Current hierarchy: **Amvest Corporation → Glamorgan Coal Company → Dorchester #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:** Amvest Corporation → Dorchester #1; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Amvest Corporation → Dorchester #1; 1976-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Dorchester Coal Company → Dorchester #1; 1976-10-01 to 1997-02-10; source msha-controller-operator-history
- **controller_controls_operator:** Amvest Corporation → Dorchester Coal Company; 1976-10-01 to 1997-02-10; source msha-controller-operator-history
- **controller_controls_mine:** (William) Scott  Moore → Dorchester #1; 1994-09-12 to 1998-02-15; source msha-controller-operator-history
- **operator_operates_mine:** Sunny Side Coal Inc → Dorchester #1; 1997-02-11 to 1998-02-15; source msha-controller-operator-history
- **controller_controls_operator:** (William) Scott  Moore → Sunny Side Coal Inc; 1997-02-11 to 1998-02-15; source msha-controller-operator-history
- **operator_operates_mine:** Glamorgan Coal Company → Dorchester #1; 1998-02-16 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Amvest Corporation → Glamorgan Coal Company; 1998-02-16 to current/open; source msha-controller-operator-history