# Relationship history for MSHA mine 0403489

Current hierarchy: **James D  Hatler → Sierra Rock Products → SIERRA ROCK PRODUCTS**

- 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:** Woods Creek Rock Plant Inc → SIERRA ROCK PRODUCTS; 1950-01-01 to 1980-06-21; source msha-controller-operator-history
- **controller_controls_mine:** Willis R  Hatler → SIERRA ROCK PRODUCTS; 1950-01-01 to 1980-06-21; source msha-controller-operator-history
- **controller_controls_operator:** Willis R  Hatler → Woods Creek Rock Plant Inc; 1950-01-01 to 1980-06-21; source msha-controller-operator-history
- **operator_operates_mine:** Sierra Rock Products → SIERRA ROCK PRODUCTS; 1980-06-22 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** James D  Hatler → SIERRA ROCK PRODUCTS; 1980-06-22 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** James D  Hatler → Sierra Rock Products; 1980-06-22 to current/open; source msha-controller-operator-history