# Relationship history for MSHA mine 4103283

Current hierarchy: **Martin Marietta Materials Inc → Martin Marietta Materials Southwest, LLC → Bedrock Plant**

- 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

- **operator_operates_mine:** Henry Griffin Construction Company → Bedrock Plant; 1985-01-01 to 2000-09-21; source msha-controller-operator-history
- **controller_controls_mine:** Henry  Griffin → Bedrock Plant; 1985-01-01 to 2000-09-21; source msha-controller-operator-history
- **controller_controls_operator:** Henry  Griffin → Henry Griffin Construction Company; 1985-01-01 to 2000-09-21; source msha-controller-operator-history
- **controller_controls_mine:** Martin Marietta Materials Inc → Bedrock Plant; 1998-12-17 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Bedrock Materials Ltd → Bedrock Plant; 2000-09-22 to 2002-09-05; source msha-controller-operator-history
- **controller_controls_mine:** Max  Duncan  et al → Bedrock Plant; 2000-09-22 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Max  Duncan  et al → Bedrock Materials Ltd; 2000-09-22 to 2002-09-05; source msha-controller-operator-history
- **operator_operates_mine:** Martin Marietta Materials Southwest Ltd → Bedrock Plant; 2002-09-06 to 2007-12-02; source msha-controller-operator-history
- **controller_controls_operator:** Martin Marietta Materials Inc → Martin Marietta Materials Southwest Ltd; 2002-09-06 to 2007-12-02; source msha-controller-operator-history
- **controller_controls_mine:** Martin Marietta Materials Inc → Bedrock Plant; 2007-11-26 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Martin Marietta Materials Southwest, LLC → Bedrock Plant; 2007-12-03 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Martin Marietta Materials Inc → Martin Marietta Materials Southwest, LLC; 2007-12-03 to current/open; source msha-controller-operator-history