# Relationship history for MSHA mine 4100848

Current hierarchy: **Coffey Don R → Three Rivers Gypsum Inc → Texas Longworth 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:** Celotex Corp → Texas Longworth Mine; 1950-01-01 to 1979-02-28; source msha-controller-operator-history
- **controller_controls_mine:** Jim Walter Corp → Texas Longworth Mine; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Jim Walter Corp → Celotex Corp; 1950-01-01 to 1979-02-28; source msha-controller-operator-history
- **operator_operates_mine:** Three Rivers Gypsum Inc → Texas Longworth Mine; 1979-03-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Coffey Don R → Texas Longworth Mine; 1979-03-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Coffey Don R → Three Rivers Gypsum Inc; 1979-03-01 to current/open; source msha-controller-operator-history