# Relationship history for MSHA mine 1300628

Current hierarchy: **Martin Marietta Materials Inc → Martin Marietta Aggregates → Clear Lake Sand**

- 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 → Clear Lake Sand; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** James W  Weaver et al → Clear Lake Sand; 1950-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Clear Lake Materials Corp → Clear Lake Sand; 1950-01-01 to 1980-05-28; source msha-controller-operator-history
- **controller_controls_mine:** Andrews Raymond T Jr → Clear Lake Sand; 1950-01-01 to 1980-05-28; source msha-controller-operator-history
- **controller_controls_operator:** Andrews Raymond T Jr → Clear Lake Materials Corp; 1950-01-01 to 1980-05-28; source msha-controller-operator-history
- **operator_operates_mine:** Weaver Construction Company → Clear Lake Sand; 1980-05-29 to 1987-02-18; source msha-controller-operator-history
- **controller_controls_operator:** James W  Weaver et al → Weaver Construction Company; 1980-05-29 to 1987-02-18; source msha-controller-operator-history
- **operator_operates_mine:** Martin Marietta Aggregates → Clear Lake Sand; 1987-02-19 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Martin Marietta Materials Inc → Martin Marietta Aggregates; 1987-02-19 to current/open; source msha-controller-operator-history