# Relationship history for MSHA mine 4603363

Current hierarchy: **Ferrell Excavating Company → Acme Limestone Company Inc → #7 Mine & Grinding Plant**

- 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:** Acme Limestone Company → #7 Mine & Grinding Plant; 1950-01-01 to 1994-04-30; source msha-controller-operator-history
- **controller_controls_mine:** W H  File Jr → #7 Mine & Grinding Plant; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** W H  File Jr → Acme Limestone Company; 1950-01-01 to 1994-04-30; source msha-controller-operator-history
- **operator_operates_mine:** Acme Limestone Company Inc → #7 Mine & Grinding Plant; 1994-05-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Ferrell Excavating Company → #7 Mine & Grinding Plant; 1994-05-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Ferrell Excavating Company → Acme Limestone Company Inc; 1994-05-01 to current/open; source msha-controller-operator-history