# Relationship history for MSHA mine 4605601

Current hierarchy: **Mashuda Corp → Mashuda Construction Company → No 29 Strip**

- 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:** Stewartstown Coal Corp → No 29 Strip; 1977-08-01 to 1981-09-23; source msha-controller-operator-history
- **controller_controls_mine:** Williford Harold → No 29 Strip; 1977-08-01 to 1981-09-23; source msha-controller-operator-history
- **controller_controls_operator:** Williford Harold → Stewartstown Coal Corp; 1977-08-01 to 1981-09-23; source msha-controller-operator-history
- **operator_operates_mine:** Mashuda Construction Company → No 29 Strip; 1981-09-24 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Mashuda Corp → No 29 Strip; 1981-09-24 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Mashuda Corp → Mashuda Construction Company; 1981-09-24 to current/open; source msha-controller-operator-history