# Relationship history for MSHA mine 2301605

Current hierarchy: **Scancem Ans & Material Service Corp → Continental Cement Company Inc → Burlington 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

- **controller_controls_mine:** Heidelberg Materials AG → Burlington Mine; 1950-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** United States Steel Corp → Burlington Mine; 1950-01-01 to 1980-10-20; source msha-controller-operator-history
- **controller_controls_mine:** USX Corp (United States Steel Corp) → Burlington Mine; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** USX Corp (United States Steel Corp) → United States Steel Corp; 1950-01-01 to 1980-10-20; source msha-controller-operator-history
- **operator_operates_mine:** Lehigh Portland Cement Company → Burlington Mine; 1980-10-21 to 1981-11-19; source msha-controller-operator-history
- **controller_controls_operator:** Heidelberg Materials AG → Lehigh Portland Cement Company; 1980-10-21 to 1981-11-19; source msha-controller-operator-history
- **operator_operates_mine:** Continental Cement Company Inc → Burlington Mine; 1981-11-20 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Scancem Ans & Material Service Corp → Burlington Mine; 1981-11-20 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Scancem Ans & Material Service Corp → Continental Cement Company Inc; 1981-11-20 to current/open; source msha-controller-operator-history