# Relationship history for MSHA mine 2900426

Current hierarchy: **Eric L  Gibson → Valley Materials → Tome 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:** Belen Sand & Gravel → Tome Pit; 1950-01-01 to 2015-09-10; source msha-controller-operator-history
- **controller_controls_mine:** William T Stone → Tome Pit; 1950-01-01 to 2004-11-30; source msha-controller-operator-history
- **controller_controls_operator:** William T Stone → Belen Sand & Gravel; 1950-01-01 to 2004-11-30; source msha-controller-operator-history
- **controller_controls_mine:** Valley Improvement Association → Tome Pit; 2004-12-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Valley Improvement Association → Belen Sand & Gravel; 2004-12-01 to 2015-09-10; source msha-controller-operator-history
- **operator_operates_mine:** Valley Materials → Tome Pit; 2015-09-11 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Eric L  Gibson → Tome Pit; 2015-09-11 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Eric L  Gibson → Valley Materials; 2015-09-11 to current/open; source msha-controller-operator-history