# Relationship history for MSHA mine 3503550

Current hierarchy: **Phil S  Hickman → Royal Rock → Royal 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:** Union Lumber Co. Inc. DBA Royal Rock → Royal Pit; 2002-01-20 to 2017-04-24; source msha-controller-operator-history
- **controller_controls_mine:** UNION LUMBER CO INC → Royal Pit; 2002-01-20 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** UNION LUMBER CO INC → Union Lumber Co. Inc. DBA Royal Rock; 2002-01-20 to 2017-04-24; source msha-controller-operator-history
- **operator_operates_mine:** Royal Rock → Royal Pit; 2017-04-25 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Phil S  Hickman → Royal Pit; 2017-04-25 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Phil S  Hickman → Royal Rock; 2017-04-25 to current/open; source msha-controller-operator-history