# Relationship history for MSHA mine 1001832

Current hierarchy: **Dowding Ray Jr → D & H Construction Company → D & H Construction (Portable Unit)**

- 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:** D & H Construction Company → D & H Construction (Portable Unit); 1988-07-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Dowding Ray Jr → D & H Construction (Portable Unit); 1988-07-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Dowding Ray Jr → D & H Construction Company; 1988-07-01 to current/open; source msha-controller-operator-history