# Relationship history for MSHA mine 1301725

Current hierarchy: **Bell Jim → Heitland Aggregates → PORTABLE ROCK 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

- **operator_operates_mine:** Heitland Brothers Construction Company → PORTABLE ROCK PLANT; 1950-01-01 to 1997-07-28; source msha-controller-operator-history
- **controller_controls_mine:** Heitland George J → PORTABLE ROCK PLANT; 1950-01-01 to 1997-07-28; source msha-controller-operator-history
- **controller_controls_operator:** Heitland George J → Heitland Brothers Construction Company; 1950-01-01 to 1997-07-28; source msha-controller-operator-history
- **operator_operates_mine:** Heitland Aggregates → PORTABLE ROCK PLANT; 1997-07-29 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Bell Jim → PORTABLE ROCK PLANT; 1997-07-29 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Bell Jim → Heitland Aggregates; 1997-07-29 to current/open; source msha-controller-operator-history