# Relationship history for MSHA mine 4103898

Current hierarchy: **Martin Marietta Materials Inc → Martin Marietta Materials Southwest Ltd → TOBIN PIT**

- 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:** Redland Plc → TOBIN PIT; 1950-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Redland Stone Products Company → TOBIN PIT; 1996-07-01 to 1998-02-10; source msha-controller-operator-history
- **controller_controls_operator:** Redland Plc → Redland Stone Products Company; 1996-07-01 to 1998-02-10; source msha-controller-operator-history
- **operator_operates_mine:** Redland Stone Products Company → TOBIN PIT; 1998-02-11 to 1998-12-16; source msha-controller-operator-history
- **controller_controls_mine:** Lafarge S A → TOBIN PIT; 1998-02-11 to 1998-12-16; source msha-controller-operator-history
- **controller_controls_operator:** Lafarge S A → Redland Stone Products Company; 1998-02-11 to 1998-12-16; source msha-controller-operator-history
- **operator_operates_mine:** Martin Marietta Materials Southwest Ltd → TOBIN PIT; 1998-12-17 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Martin Marietta Materials Inc → TOBIN PIT; 1998-12-17 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Martin Marietta Materials Inc → Martin Marietta Materials Southwest Ltd; 1998-12-17 to current/open; source msha-controller-operator-history