# Relationship history for MSHA mine 0405142

Current hierarchy: **Vulcan Materials Company → Superior Ready Mix Concrete L.P. → EL CENTRO PROCESSING**

- 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:** John A  Ryerson → EL CENTRO PROCESSING; 1950-01-01 to 1994-11-30; source msha-controller-operator-history
- **controller_controls_mine:** J Brouwer Investments Inc Et Al → EL CENTRO PROCESSING; 1979-09-01 to 2025-04-27; source msha-controller-operator-history
- **operator_operates_mine:** Desert Gravel Company → EL CENTRO PROCESSING; 1991-03-01 to 1994-11-30; source msha-controller-operator-history
- **controller_controls_operator:** John A  Ryerson → Desert Gravel Company; 1991-03-01 to 1994-11-30; source msha-controller-operator-history
- **operator_operates_mine:** RYERSON → EL CENTRO PROCESSING; 1994-12-01 to 2006-01-12; source msha-controller-operator-history
- **controller_controls_mine:** William R  Hoffman Et Al → EL CENTRO PROCESSING; 1994-12-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** William R  Hoffman Et Al → RYERSON; 1994-12-01 to 2006-01-12; source msha-controller-operator-history
- **controller_controls_operator:** William F  Lee Et Al → RYERSON; 1994-12-01 to 2006-01-12; source msha-controller-operator-history
- **operator_operates_mine:** Superior Ready Mix Concrete L.P. → EL CENTRO PROCESSING; 2006-01-13 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** J Brouwer Investments Inc Et Al → Superior Ready Mix Concrete L.P.; 2006-01-13 to 2025-04-27; source msha-controller-operator-history
- **controller_controls_mine:** Vulcan Materials Company → EL CENTRO PROCESSING; 2025-04-28 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Vulcan Materials Company → Superior Ready Mix Concrete L.P.; 2025-04-28 to current/open; source msha-controller-operator-history