# Relationship history for MSHA mine 1400638

Current hierarchy: **Dane Q Barclay → Alsop Sand Company Inc → Scandia Pit No 2**

- 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:** Alsop Sand Company Inc → Scandia Pit No 2; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** David H  Barclay et al → Scandia Pit No 2; 1950-01-01 to 2017-05-10; source msha-controller-operator-history
- **controller_controls_operator:** David H  Barclay et al → Alsop Sand Company Inc; 1950-01-01 to 2017-05-10; source msha-controller-operator-history
- **controller_controls_operator:** Dane Q  Barclay et al → Alsop Sand Company Inc; 1950-01-01 to 2017-05-10; source msha-controller-operator-history
- **controller_controls_mine:** Dane Q Barclay → Scandia Pit No 2; 2017-05-11 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Dane Q Barclay → Alsop Sand Company Inc; 2017-05-11 to current/open; source msha-controller-operator-history