# Relationship history for MSHA mine 0900810

Current hierarchy: **Lhoist Group → Lhoist North America of Tennessee, Inc. → Dalton Mill**

- 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:** Franklin Industries Inc → Dalton Mill; 1950-01-01 to 2006-11-30; source msha-controller-operator-history
- **operator_operates_mine:** Tac Industries Inc → Dalton Mill; 1950-01-01 to 1988-11-30; source msha-controller-operator-history
- **controller_controls_mine:** Gary D  Curtin → Dalton Mill; 1950-01-01 to 1988-11-30; source msha-controller-operator-history
- **controller_controls_operator:** Gary D  Curtin → Tac Industries Inc; 1950-01-01 to 1988-11-30; source msha-controller-operator-history
- **operator_operates_mine:** Lhoist North America of Tennessee, Inc. → Dalton Mill; 1988-12-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Franklin Industries Inc → Lhoist North America of Tennessee, Inc.; 1988-12-01 to 2006-11-30; source msha-controller-operator-history
- **controller_controls_mine:** Lhoist Group → Dalton Mill; 2006-12-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Lhoist Group → Lhoist North America of Tennessee, Inc.; 2006-12-01 to current/open; source msha-controller-operator-history