# Relationship history for MSHA mine 4001690

Current hierarchy: **Lowe Ralph → L & L Coal Company → No 1 Surface**

- 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

- **controller_controls_mine:** Lowe Ralph Et Al → No 1 Surface; 1950-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Dupont Smith Enterprises → No 1 Surface; 1974-11-01 to 1980-11-24; source msha-controller-operator-history
- **controller_controls_mine:** Smith Robert D → No 1 Surface; 1974-11-01 to 1980-11-24; source msha-controller-operator-history
- **controller_controls_operator:** Smith Robert D → Dupont Smith Enterprises; 1974-11-01 to 1980-11-24; source msha-controller-operator-history
- **operator_operates_mine:** L & L Coal Company → No 1 Surface; 1980-11-25 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Lowe Ralph Et Al → L & L Coal Company; 1980-11-25 to current/open; source msha-controller-operator-history