# Relationship history for MSHA mine 3800710

Current hierarchy: **Martin Marietta Materials Inc → Palmetto Sand Co., Inc. → Palmetto Sand Mine**

- 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:** Florence H  Thomas → Palmetto Sand Mine; 1984-03-21 to 2006-11-30; source msha-controller-operator-history
- **operator_operates_mine:** Palmetto Sand Co., Inc. → Palmetto Sand Mine; 2004-04-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Florence H  Thomas → Palmetto Sand Co., Inc.; 2004-04-01 to 2006-11-30; source msha-controller-operator-history
- **controller_controls_mine:** Hamer P Thomas → Palmetto Sand Mine; 2006-12-01 to 2018-10-25; source msha-controller-operator-history
- **controller_controls_operator:** Hamer P Thomas → Palmetto Sand Co., Inc.; 2006-12-01 to 2018-10-25; source msha-controller-operator-history
- **controller_controls_mine:** Blue Water Industries Holdings LLC → Palmetto Sand Mine; 2018-10-26 to 2024-04-04; source msha-controller-operator-history
- **controller_controls_operator:** Blue Water Industries Holdings LLC → Palmetto Sand Co., Inc.; 2018-10-26 to 2024-04-04; source msha-controller-operator-history
- **controller_controls_mine:** Martin Marietta Materials Inc → Palmetto Sand Mine; 2024-04-05 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Martin Marietta Materials Inc → Palmetto Sand Co., Inc.; 2024-04-05 to current/open; source msha-controller-operator-history