# Relationship history for MSHA mine 2302567

Current hierarchy: **Martin Marietta Materials Inc → Martin Marietta Materials, Inc. → South Portable 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

- **controller_controls_mine:** Martin Marietta Materials Inc → South Portable Plant; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** 42 North Resources Partners II LP et al → South Portable Plant; 2021-07-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** New Frontier Materials Operations Alpha LLC → South Portable Plant; 2022-01-24 to 2026-06-14; source msha-controller-operator-history
- **controller_controls_operator:** 42 North Resources Partners II LP et al → New Frontier Materials Operations Alpha LLC; 2022-01-24 to 2026-06-14; source msha-controller-operator-history
- **controller_controls_operator:** RWNIH-OP Holdings LLC et al → New Frontier Materials Operations Alpha LLC; 2022-01-24 to 2026-06-14; source msha-controller-operator-history
- **controller_controls_operator:** PEPI Capital, L.P. et al → New Frontier Materials Operations Alpha LLC; 2022-01-24 to 2026-06-14; source msha-controller-operator-history
- **operator_operates_mine:** Martin Marietta Materials, Inc. → South Portable Plant; 2026-06-15 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Martin Marietta Materials Inc → Martin Marietta Materials, Inc.; 2026-06-15 to current/open; source msha-controller-operator-history