# Relationship history for MSHA mine 1514716

Current hierarchy: **Hall David → R & D Construction Company → R&D Construction**

- 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:** R & D Construction Company → R&D Construction; 1984-07-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Hall David Et Al → R&D Construction; 1984-07-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Hall David Et Al → R & D Construction Company; 1984-07-01 to current/open; source msha-controller-operator-history