# Relationship history for MSHA mine 1202038

Current hierarchy: **Martin Marietta Materials Inc → Martin Marietta Materials Inc → Waverly Sand & 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: 2026-10-17T05:35:58.500035+00:00

## Valid-time edges

- **controller_controls_mine:** Martin Marietta Materials Inc → Waverly Sand & Gravel; 1950-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Waverly Aggregate Inc → Waverly Sand & Gravel; 1988-10-01 to 1991-04-07; source msha-controller-operator-history
- **controller_controls_mine:** John  Loudermilk → Waverly Sand & Gravel; 1988-10-01 to 1991-04-07; source msha-controller-operator-history
- **controller_controls_operator:** John  Loudermilk → Waverly Aggregate Inc; 1988-10-01 to 1991-04-07; source msha-controller-operator-history
- **operator_operates_mine:** Martin Marietta Aggregates → Waverly Sand & Gravel; 1991-04-08 to 2005-05-19; source msha-controller-operator-history
- **controller_controls_operator:** Martin Marietta Materials Inc → Martin Marietta Aggregates; 1991-04-08 to 2005-05-19; source msha-controller-operator-history
- **operator_operates_mine:** Martin Marietta Materials Inc → Waverly Sand & Gravel; 2005-05-20 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Martin Marietta Materials Inc → Martin Marietta Materials Inc; 2005-05-20 to current/open; source msha-controller-operator-history