# Relationship history for MSHA mine 0900317

Current hierarchy: **Vulcan Materials Company → Vulcan Construction Materials, L.P. → WALKER COUNTY QUARRY**

- 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:** Legacy Vulcan Corp (Form:Vulcan Materials Co) → WALKER COUNTY QUARRY; 1950-01-01 to 2007-11-15; source msha-controller-operator-history
- **operator_operates_mine:** Patton Rock Products Corp → WALKER COUNTY QUARRY; 1950-01-01 to 1999-03-31; source msha-controller-operator-history
- **controller_controls_mine:** James E Patton → WALKER COUNTY QUARRY; 1950-01-01 to 1999-03-31; source msha-controller-operator-history
- **controller_controls_operator:** James E Patton → Patton Rock Products Corp; 1950-01-01 to 1999-03-31; source msha-controller-operator-history
- **operator_operates_mine:** Vulcan Construction Materials, L.P. → WALKER COUNTY QUARRY; 1999-04-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Legacy Vulcan Corp (Form:Vulcan Materials Co) → Vulcan Construction Materials, L.P.; 1999-04-01 to 2007-11-15; source msha-controller-operator-history
- **controller_controls_mine:** Vulcan Materials Company → WALKER COUNTY QUARRY; 2007-11-16 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Vulcan Materials Company → Vulcan Construction Materials, L.P.; 2007-11-16 to current/open; source msha-controller-operator-history