# Relationship history for MSHA mine 1300736

Current hierarchy: **William  Yohn → Wright Materials Company → Belmond 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: 2026-10-17T05:35:58.500035+00:00

## Valid-time edges

- **operator_operates_mine:** Nelson Sand & Gravel Company Inc → Belmond Pit; 1950-01-01 to 1990-07-08; source msha-controller-operator-history
- **controller_controls_mine:** Eugene  Nelson → Belmond Pit; 1950-01-01 to 1990-07-08; source msha-controller-operator-history
- **controller_controls_operator:** Eugene  Nelson → Nelson Sand & Gravel Company Inc; 1950-01-01 to 1990-07-08; source msha-controller-operator-history
- **operator_operates_mine:** Wright Materials Company → Belmond Pit; 1990-07-09 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** William  Yohn → Belmond Pit; 1990-07-09 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** William  Yohn → Wright Materials Company; 1990-07-09 to current/open; source msha-controller-operator-history