# Relationship history for MSHA mine 4102876

Current hierarchy: **Kaiser Cement Corp → Amistad Fuel Company → Little Bull Creek Coal 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: 2026-10-18T09:31:49.615908+00:00

## Valid-time edges

- **operator_operates_mine:** Zeus Corp → Little Bull Creek Coal Mine; 1979-06-01 to 1980-12-30; source msha-controller-operator-history
- **controller_controls_mine:** Texas Architectural Aggregate Inc → Little Bull Creek Coal Mine; 1979-06-01 to 1980-12-30; source msha-controller-operator-history
- **controller_controls_operator:** Texas Architectural Aggregate Inc → Zeus Corp; 1979-06-01 to 1980-12-30; source msha-controller-operator-history
- **operator_operates_mine:** Amistad Fuel Company → Little Bull Creek Coal Mine; 1980-12-31 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Kaiser Cement Corp → Little Bull Creek Coal Mine; 1980-12-31 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Kaiser Cement Corp → Amistad Fuel Company; 1980-12-31 to current/open; source msha-controller-operator-history