# Relationship history for MSHA mine 1301859

Current hierarchy: **David B Carlson; Frederic Reed  Carlson → Carlson Materials Company Inc → La Costa 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

- **controller_controls_mine:** Frederic Reed  Carlson et al → La Costa Pit; 1950-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Carlson Materials Company Inc → La Costa Pit; 1978-03-09 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Frederic Reed  Carlson et al → Carlson Materials Company Inc; 1978-03-09 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** David B Carlson et al → Carlson Materials Company Inc; 1978-03-09 to current/open; source msha-controller-operator-history