# Relationship history for MSHA mine 4002169

Current hierarchy: **William D  Dement → Dement Construction Company → Bringle Pit**

- 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 A Hadley Construction Company Inc → Bringle Pit; 1950-01-01 to 1979-09-30; source msha-controller-operator-history
- **controller_controls_mine:** Hadley J A Construction Company Inc → Bringle Pit; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Hadley J A Construction Company Inc → J A Hadley Construction Company Inc; 1950-01-01 to 1979-09-30; source msha-controller-operator-history
- **controller_controls_mine:** Rogers Group Inc → Bringle Pit; 1950-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Rogers Group Inc → Bringle Pit; 1979-10-01 to 1990-04-30; source msha-controller-operator-history
- **controller_controls_operator:** Rogers Group Inc → Rogers Group Inc; 1979-10-01 to 1990-04-30; source msha-controller-operator-history
- **controller_controls_mine:** William D  Dement → Bringle Pit; 1984-10-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Dement Construction Company → Bringle Pit; 1990-05-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** William D  Dement → Dement Construction Company; 1990-05-01 to current/open; source msha-controller-operator-history