# Relationship history for MSHA mine 3200715

Current hierarchy: **Darwayne  Crandall; Roland  Crandall → Crandall Construction → UNIT 01 Wallman 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:** Crandall Construction → UNIT 01 Wallman Pit; 1990-05-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Roland  Crandall  et al → UNIT 01 Wallman Pit; 1990-05-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Roland  Crandall  et al → Crandall Construction; 1990-05-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Darwayne  Crandall  et al → Crandall Construction; 1990-05-01 to current/open; source msha-controller-operator-history