# Relationship history for MSHA mine 3900783

Current hierarchy: **Scherer Bob → Scherer & Son Mining → Henwood 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:** Bush Mining Company → Henwood Mine; 1950-01-01 to 1985-09-17; source msha-controller-operator-history
- **controller_controls_mine:** Bush Don → Henwood Mine; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Bush Don → Bush Mining Company; 1950-01-01 to 1985-09-17; source msha-controller-operator-history
- **operator_operates_mine:** Scherer & Son Mining → Henwood Mine; 1985-09-18 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Scherer Bob → Henwood Mine; 1985-09-18 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Scherer Bob → Scherer & Son Mining; 1985-09-18 to current/open; source msha-controller-operator-history