# Relationship history for MSHA mine 3604629

Current hierarchy: **David S  Himmelberger → Primrose Coal Company → Primrose Slope**

- 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:** Lucas Mining Company → Primrose Slope; 1973-01-01 to 1991-09-30; source msha-controller-operator-history
- **controller_controls_mine:** Lucas Larry → Primrose Slope; 1973-01-01 to 1991-09-30; source msha-controller-operator-history
- **controller_controls_operator:** Lucas Larry → Lucas Mining Company; 1973-01-01 to 1991-09-30; source msha-controller-operator-history
- **operator_operates_mine:** Primrose Coal Company → Primrose Slope; 1991-10-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** David S  Himmelberger et al → Primrose Slope; 1991-10-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** David S  Himmelberger et al → Primrose Coal Company; 1991-10-01 to current/open; source msha-controller-operator-history