# Relationship history for MSHA mine 3800721

Current hierarchy: **Martin Marietta Materials Inc → Martin Marietta Materials, Inc. → Loamy Sand and Gravel**

- Valid-time bounds: inclusive, date granularity
- Null end: open-ended in the upstream history row; not independent proof of present control
- Transaction-time observation: 2026-10-18T09:31:49.615908+00:00

## Valid-time edges

- **controller_controls_mine:** Martin Marietta Materials Inc → Loamy Sand and Gravel; 1950-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Loamy,LLC → Loamy Sand and Gravel; 2008-05-08 to 2010-10-30; source msha-controller-operator-history
- **controller_controls_mine:** Paul D  McMillan et al → Loamy Sand and Gravel; 2008-05-08 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Paul D  McMillan et al → Loamy,LLC; 2008-05-08 to 2010-10-30; source msha-controller-operator-history
- **controller_controls_operator:** Thomas C  Rowland III et al → Loamy,LLC; 2008-05-08 to 2010-10-30; source msha-controller-operator-history
- **operator_operates_mine:** Martin Marietta Materials, Inc. → Loamy Sand and Gravel; 2010-10-31 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Martin Marietta Materials Inc → Martin Marietta Materials, Inc.; 2010-10-31 to current/open; source msha-controller-operator-history