# Relationship history for MSHA mine 4001737

Current hierarchy: **Cofer William D → Coach Coal Inc → #1 Strip**

- 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

- **operator_operates_mine:** J J & M Coal Company → #1 Strip; 1975-01-01 to 1977-04-26; source msha-controller-operator-history
- **controller_controls_mine:** Jackson Glen & Jimmy--Henry Melhorn → #1 Strip; 1975-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Jackson Glen & Jimmy--Henry Melhorn → J J & M Coal Company; 1975-01-01 to 1977-04-26; source msha-controller-operator-history
- **operator_operates_mine:** Coach Coal Inc → #1 Strip; 1977-04-27 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Cofer William D → #1 Strip; 1977-04-27 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Cofer William D → Coach Coal Inc; 1977-04-27 to current/open; source msha-controller-operator-history