# Relationship history for MSHA mine 0404508

Current hierarchy: **Spence David T → Humbug Mining Company Inc → Golden Girl**

- 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:** Humbug Mining Company Inc → Golden Girl; 1981-05-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Spence David T → Golden Girl; 1981-05-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Spence David T → Humbug Mining Company Inc; 1981-05-01 to current/open; source msha-controller-operator-history