# Relationship history for MSHA mine 1401457

Current hierarchy: **Martin Marietta Materials Inc → Hunt Martin Materials L.L.C. → CRAWFORD 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:** R B  Killough → CRAWFORD QUARRY; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Hunt Midwest Enterprises → CRAWFORD QUARRY; 1985-06-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Killough Quarries Inc → CRAWFORD QUARRY; 1985-07-01 to 1995-05-31; source msha-controller-operator-history
- **controller_controls_operator:** R B  Killough → Killough Quarries Inc; 1985-07-01 to 1995-05-31; source msha-controller-operator-history
- **operator_operates_mine:** Hunt Midwest Mining Inc → CRAWFORD QUARRY; 1995-06-01 to 2005-01-01; source msha-controller-operator-history
- **controller_controls_operator:** Hunt Midwest Enterprises → Hunt Midwest Mining Inc; 1995-06-01 to 2005-01-01; source msha-controller-operator-history
- **operator_operates_mine:** Hunt Martin Materials L.L.C. → CRAWFORD QUARRY; 2005-01-02 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Martin Marietta Materials Inc et al → CRAWFORD QUARRY; 2005-02-01 to 2014-04-02; source msha-controller-operator-history
- **controller_controls_operator:** Martin Marietta Materials Inc et al → Hunt Martin Materials L.L.C.; 2005-02-01 to 2014-04-02; source msha-controller-operator-history
- **controller_controls_operator:** Hunt Midwest Enterprises et al → Hunt Martin Materials L.L.C.; 2005-02-01 to 2014-04-02; source msha-controller-operator-history
- **controller_controls_mine:** Martin Marietta Materials Inc → CRAWFORD QUARRY; 2014-04-03 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Martin Marietta Materials Inc → Hunt Martin Materials L.L.C.; 2014-04-03 to current/open; source msha-controller-operator-history