# Relationship history for MSHA mine 2900478

Current hierarchy: **Calmat Company → Calmat Company Of New Mexico → Sandia 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

- **operator_operates_mine:** Shiver Construction Company Inc → Sandia Pit; 1950-01-01 to 1984-01-31; source msha-controller-operator-history
- **controller_controls_mine:** James B  Shiver → Sandia Pit; 1950-01-01 to 1984-01-31; source msha-controller-operator-history
- **controller_controls_operator:** James B  Shiver → Shiver Construction Company Inc; 1950-01-01 to 1984-01-31; source msha-controller-operator-history
- **operator_operates_mine:** S & S Aggregates Inc → Sandia Pit; 1984-02-01 to 1989-02-12; source msha-controller-operator-history
- **controller_controls_mine:** Sundt Corp → Sandia Pit; 1984-02-01 to 1989-02-12; source msha-controller-operator-history
- **controller_controls_operator:** Sundt Corp → S & S Aggregates Inc; 1984-02-01 to 1989-02-12; source msha-controller-operator-history
- **operator_operates_mine:** Calmat Company Of New Mexico → Sandia Pit; 1989-02-13 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Calmat Company → Sandia Pit; 1989-02-13 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Calmat Company → Calmat Company Of New Mexico; 1989-02-13 to current/open; source msha-controller-operator-history