# Relationship history for MSHA mine 1400164

Current hierarchy: **Martin Marietta Materials Inc → Martin Marietta Materials, Inc. → KANSAS FALLS 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 → KANSAS FALLS QUARRY; 1950-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Walker Stone Company Inc → KANSAS FALLS QUARRY; 1950-01-01 to 2001-08-02; source msha-controller-operator-history
- **controller_controls_mine:** David S  Walker → KANSAS FALLS QUARRY; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** David S  Walker → Walker Stone Company Inc; 1950-01-01 to 2001-08-02; source msha-controller-operator-history
- **operator_operates_mine:** Martin Marietta Aggregates → KANSAS FALLS QUARRY; 2001-08-03 to 2005-05-23; source msha-controller-operator-history
- **controller_controls_operator:** Martin Marietta Materials Inc → Martin Marietta Aggregates; 2001-08-03 to 2005-05-23; source msha-controller-operator-history
- **operator_operates_mine:** Martin Marietta Materials, Inc. → KANSAS FALLS QUARRY; 2005-05-24 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Martin Marietta Materials Inc → Martin Marietta Materials, Inc.; 2005-05-24 to current/open; source msha-controller-operator-history