# Relationship history for MSHA mine 2300070

Current hierarchy: **Martin Marietta Materials Inc → Martin Marietta Materials, Inc. → APPLETON QUARRY**

- 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:** Martin Marietta Materials Inc → APPLETON QUARRY; 1950-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Farmers Limestone Company Inc → APPLETON QUARRY; 1950-01-01 to 1988-03-14; source msha-controller-operator-history
- **controller_controls_mine:** R C  Schnurbusch → APPLETON QUARRY; 1950-01-01 to 1988-03-14; source msha-controller-operator-history
- **controller_controls_operator:** R C  Schnurbusch → Farmers Limestone Company Inc; 1950-01-01 to 1988-03-14; source msha-controller-operator-history
- **operator_operates_mine:** Farmers Limestone Company → APPLETON QUARRY; 1988-03-15 to 1997-02-25; source msha-controller-operator-history
- **controller_controls_mine:** Richard  Hurst  et al → APPLETON QUARRY; 1988-03-15 to 1997-02-25; source msha-controller-operator-history
- **controller_controls_operator:** Richard  Hurst  et al → Farmers Limestone Company; 1988-03-15 to 1997-02-25; source msha-controller-operator-history
- **operator_operates_mine:** Martin Marietta Aggregates → APPLETON QUARRY; 1997-02-26 to 2005-05-18; source msha-controller-operator-history
- **controller_controls_operator:** Martin Marietta Materials Inc → Martin Marietta Aggregates; 1997-02-26 to 2005-05-18; source msha-controller-operator-history
- **operator_operates_mine:** Martin Marietta Materials, Inc. → APPLETON QUARRY; 2005-05-19 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Martin Marietta Materials Inc → Martin Marietta Materials, Inc.; 2005-05-19 to current/open; source msha-controller-operator-history