# Relationship history for MSHA mine 0200693

Current hierarchy: **Cemex S A → Sunward Materials → DREXEL 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:** Columbia Building Materials Inc → DREXEL PIT; 1950-01-01 to 1982-12-13; source msha-controller-operator-history
- **controller_controls_mine:** Columbia Consolidated Corp → DREXEL PIT; 1950-01-01 to 1982-12-13; source msha-controller-operator-history
- **controller_controls_operator:** Columbia Consolidated Corp → Columbia Building Materials Inc; 1950-01-01 to 1982-12-13; source msha-controller-operator-history
- **controller_controls_mine:** Roland  May → DREXEL PIT; 1982-12-07 to 1986-01-15; source msha-controller-operator-history
- **operator_operates_mine:** Columbia Materials → DREXEL PIT; 1982-12-14 to 1986-01-15; source msha-controller-operator-history
- **controller_controls_operator:** Roland  May → Columbia Materials; 1982-12-14 to 1986-01-15; source msha-controller-operator-history
- **controller_controls_mine:** Blue Circle Industries Plc → DREXEL PIT; 1984-05-03 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Blue Circle West → DREXEL PIT; 1986-01-16 to 1989-07-31; source msha-controller-operator-history
- **controller_controls_operator:** Blue Circle Industries Plc → Blue Circle West; 1986-01-16 to 1989-07-31; source msha-controller-operator-history
- **operator_operates_mine:** B C W Inc → DREXEL PIT; 1989-08-01 to 1990-09-30; source msha-controller-operator-history
- **controller_controls_mine:** Empresas Tolteca → DREXEL PIT; 1989-08-01 to 1990-09-30; source msha-controller-operator-history
- **controller_controls_operator:** Empresas Tolteca → B C W Inc; 1989-08-01 to 1990-09-30; source msha-controller-operator-history
- **operator_operates_mine:** Sunward Materials → DREXEL PIT; 1990-10-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Cemex S A → DREXEL PIT; 1990-10-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Cemex S A → Sunward Materials; 1990-10-01 to current/open; source msha-controller-operator-history