# Relationship history for MSHA mine 1600542

Current hierarchy: **Joshlin Darrell & Wayne Powell → J & W Joshlin Sand & Gravel → Joshlin Dredge And 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:** Gravel Production Company → Joshlin Dredge And Pit; 1950-01-01 to 1979-05-05; source msha-controller-operator-history
- **controller_controls_mine:** David E  Joshlin → Joshlin Dredge And Pit; 1950-01-01 to 1981-09-01; source msha-controller-operator-history
- **controller_controls_operator:** David E  Joshlin → Gravel Production Company; 1950-01-01 to 1979-05-05; source msha-controller-operator-history
- **operator_operates_mine:** J & W Joshlin Sand & Gravel → Joshlin Dredge And Pit; 1979-05-06 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Joshlin Darrell & Wayne Powell → Joshlin Dredge And Pit; 1979-05-06 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Joshlin Darrell & Wayne Powell → J & W Joshlin Sand & Gravel; 1979-05-06 to current/open; source msha-controller-operator-history