# Relationship history for MSHA mine 3501270

Current hierarchy: **Gurley Phillip S → Jenco Enterprises Inc → Jensen Sand & Gravel 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:** Jensens Shale Pit Inc → Jensen Sand & Gravel Pit; 1950-01-01 to 1981-03-19; source msha-controller-operator-history
- **controller_controls_mine:** Jensen Burton J → Jensen Sand & Gravel Pit; 1950-01-01 to 1981-09-01; source msha-controller-operator-history
- **controller_controls_operator:** Jensen Burton J → Jensens Shale Pit Inc; 1950-01-01 to 1981-03-19; source msha-controller-operator-history
- **operator_operates_mine:** Jenco Enterprises Inc → Jensen Sand & Gravel Pit; 1981-03-20 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Gurley Phillip S → Jensen Sand & Gravel Pit; 1981-03-20 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Gurley Phillip S → Jenco Enterprises Inc; 1981-03-20 to current/open; source msha-controller-operator-history