# Relationship history for MSHA mine 2002434

Current hierarchy: **VOTORANTIM CIMENTOS → St. Marys Cement → St Marys Cement-Detroit**

- Valid-time bounds: inclusive, date granularity
- Null end: open-ended in the upstream history row; not independent proof of present control
- Transaction-time observation: 2026-10-17T05:35:58.500035+00:00

## Valid-time edges

- **operator_operates_mine:** Peerless Cement Company → St Marys Cement-Detroit; 1979-01-01 to 1979-12-06; source msha-controller-operator-history
- **controller_controls_mine:** Amcord Inc → St Marys Cement-Detroit; 1979-01-01 to 1979-12-06; source msha-controller-operator-history
- **controller_controls_operator:** Amcord Inc → Peerless Cement Company; 1979-01-01 to 1979-12-06; source msha-controller-operator-history
- **operator_operates_mine:** Peerless Cement Company → St Marys Cement-Detroit; 1979-12-07 to 1984-07-31; source msha-controller-operator-history
- **controller_controls_mine:** Hanson PLC → St Marys Cement-Detroit; 1979-12-07 to 1984-07-31; source msha-controller-operator-history
- **controller_controls_operator:** Hanson PLC → Peerless Cement Company; 1979-12-07 to 1984-07-31; source msha-controller-operator-history
- **controller_controls_mine:** Blue Circle Industries Plc → St Marys Cement-Detroit; 1983-05-18 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** St Marys Cement Company → St Marys Cement-Detroit; 1984-08-01 to 1997-03-31; source msha-controller-operator-history
- **controller_controls_mine:** St Marys Cement Corp → St Marys Cement-Detroit; 1984-08-01 to 1997-03-31; source msha-controller-operator-history
- **controller_controls_operator:** St Marys Cement Corp → St Marys Cement Company; 1984-08-01 to 1997-03-31; source msha-controller-operator-history
- **operator_operates_mine:** Blue Circle Inc → St Marys Cement-Detroit; 1997-04-01 to 2001-07-31; source msha-controller-operator-history
- **controller_controls_operator:** Blue Circle Industries Plc → Blue Circle Inc; 1997-04-01 to 2001-07-31; source msha-controller-operator-history
- **operator_operates_mine:** St. Marys Cement → St Marys Cement-Detroit; 2001-08-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** VOTORANTIM CIMENTOS → St Marys Cement-Detroit; 2001-08-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** VOTORANTIM CIMENTOS → St. Marys Cement; 2001-08-01 to current/open; source msha-controller-operator-history