# Relationship history for MSHA mine 2901894

Current hierarchy: **Tommy J  Blankenship → Tommy Blankenship Sand & Gravel → Tommy Blankenship 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:** Tommy Blankenship Sand & Gravel → Tommy Blankenship Pit; 1982-12-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Tommy J  Blankenship → Tommy Blankenship Pit; 1982-12-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Tommy J  Blankenship → Tommy Blankenship Sand & Gravel; 1982-12-01 to current/open; source msha-controller-operator-history