# Relationship history for MSHA mine 1505377

Current hierarchy: **Spurlock Hart → Castle Rock Coal Company → No 3 Mine**

- 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:** M & B Coal Company Inc → No 3 Mine; 1950-01-01 to 1974-11-30; source msha-controller-operator-history
- **controller_controls_mine:** Benjamin R.  Bennett → No 3 Mine; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Benjamin R.  Bennett → M & B Coal Company Inc; 1950-01-01 to 1974-11-30; source msha-controller-operator-history
- **controller_controls_mine:** Spurlock Hart → No 3 Mine; 1950-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Castle Rock Coal Company → No 3 Mine; 1974-12-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Spurlock Hart → Castle Rock Coal Company; 1974-12-01 to current/open; source msha-controller-operator-history