# Relationship history for MSHA mine 0503489

Current hierarchy: **Daryl R  Webster; Lydia  Webster → Webster Sand & Gravel, LLC → WEST TENNESSEE 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

- **controller_controls_mine:** Webster Ellis B → WEST TENNESSEE PIT; 1950-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Webster Sand & Gravel Inc → WEST TENNESSEE PIT; 1979-01-01 to 1983-06-07; source msha-controller-operator-history
- **controller_controls_operator:** Webster Ellis B → Webster Sand & Gravel Inc; 1979-01-01 to 1983-06-07; source msha-controller-operator-history
- **operator_operates_mine:** Websters Sand & Gravel → WEST TENNESSEE PIT; 1983-06-08 to 2008-12-31; source msha-controller-operator-history
- **controller_controls_mine:** Charles J Webster Estate → WEST TENNESSEE PIT; 1983-06-08 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Charles J Webster Estate → Websters Sand & Gravel; 1983-06-08 to 2008-12-31; source msha-controller-operator-history
- **operator_operates_mine:** Webster Sand & Gravel, LLC → WEST TENNESSEE PIT; 2009-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Daryl R  Webster et al → WEST TENNESSEE PIT; 2009-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Daryl R  Webster et al → Webster Sand & Gravel, LLC; 2009-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Lydia  Webster et al → Webster Sand & Gravel, LLC; 2009-01-01 to current/open; source msha-controller-operator-history