# Relationship history for MSHA mine 0900272

Current hierarchy: **Holcim Ltd → Lafarge Building Materials Incorporated → Franklinton 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:** Cornell-Young Company → Franklinton Pit; 1950-01-01 to 1990-10-21; source msha-controller-operator-history
- **controller_controls_mine:** R M  Young → Franklinton Pit; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** R M  Young → Cornell-Young Company; 1950-01-01 to 1990-10-21; source msha-controller-operator-history
- **controller_controls_mine:** Blue Circle Industries Plc → Franklinton Pit; 1987-07-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Blue Circle Materials Inc → Franklinton Pit; 1990-10-22 to 2001-07-11; source msha-controller-operator-history
- **controller_controls_operator:** Blue Circle Industries Plc → Blue Circle Materials Inc; 1990-10-22 to 2001-07-11; source msha-controller-operator-history
- **operator_operates_mine:** Lafarge Building Materials Incorporated → Franklinton Pit; 2001-07-12 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Lafarge S A → Franklinton Pit; 2001-07-12 to 2015-07-09; source msha-controller-operator-history
- **controller_controls_operator:** Lafarge S A → Lafarge Building Materials Incorporated; 2001-07-12 to 2015-07-09; source msha-controller-operator-history
- **controller_controls_mine:** Holcim Ltd → Franklinton Pit; 2015-07-10 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Holcim Ltd → Lafarge Building Materials Incorporated; 2015-07-10 to current/open; source msha-controller-operator-history