# Relationship history for MSHA mine 1600929

Current hierarchy: **Lafarge S A → General Portland Inc → Forest Hill Plant 57**

- 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:** General Portland Inc → Forest Hill Plant 57; 1950-01-01 to 1981-11-11; source msha-controller-operator-history
- **operator_operates_mine:** D Fruge Contractors Inc → Forest Hill Plant 57; 1978-12-01 to 1980-06-17; source msha-controller-operator-history
- **controller_controls_mine:** Fruge Glenn → Forest Hill Plant 57; 1978-12-01 to 1980-06-17; source msha-controller-operator-history
- **controller_controls_operator:** Fruge Glenn → D Fruge Contractors Inc; 1978-12-01 to 1980-06-17; source msha-controller-operator-history
- **operator_operates_mine:** Trinity South Div-General Portland Inc → Forest Hill Plant 57; 1980-06-18 to 1981-11-11; source msha-controller-operator-history
- **controller_controls_operator:** General Portland Inc → Trinity South Div-General Portland Inc; 1980-06-18 to 1981-11-11; source msha-controller-operator-history
- **operator_operates_mine:** General Portland Inc → Forest Hill Plant 57; 1981-11-12 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Lafarge S A → Forest Hill Plant 57; 1981-11-12 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Lafarge S A → General Portland Inc; 1981-11-12 to current/open; source msha-controller-operator-history