# Relationship history for MSHA mine 0801203

Current hierarchy: **Martin Marietta Materials Inc → Martin Marietta Materials, Inc → Fort Myers 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: 2026-10-17T05:35:58.500035+00:00

## Valid-time edges

- **controller_controls_mine:** Martin Marietta Materials Inc → Fort Myers Quarry; 1950-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Alico Lake Inc → Fort Myers Quarry; 1992-09-01 to 2003-06-30; source msha-controller-operator-history
- **controller_controls_mine:** Tim G  Youngquist et al → Fort Myers Quarry; 1992-09-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Tim G  Youngquist et al → Alico Lake Inc; 1992-09-01 to 2003-06-30; source msha-controller-operator-history
- **controller_controls_operator:** Harvey  Youngquist et al → Alico Lake Inc; 1992-09-01 to 2003-06-30; source msha-controller-operator-history
- **controller_controls_mine:** Harvey  Youngquist et al → Fort Myers Quarry; 1997-06-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Youngquist Brothers Rock Inc. → Fort Myers Quarry; 2003-07-01 to 2024-10-24; source msha-controller-operator-history
- **controller_controls_operator:** Harvey  Youngquist et al → Youngquist Brothers Rock Inc.; 2003-07-01 to 2024-10-24; source msha-controller-operator-history
- **controller_controls_operator:** Tim G  Youngquist et al → Youngquist Brothers Rock Inc.; 2003-07-01 to 2024-10-24; source msha-controller-operator-history
- **operator_operates_mine:** Martin Marietta Materials, Inc → Fort Myers Quarry; 2024-10-25 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Martin Marietta Materials Inc → Martin Marietta Materials, Inc; 2024-10-25 to current/open; source msha-controller-operator-history