# Relationship history for MSHA mine 0503140

Current hierarchy: **Kofford Kay G → Emrx Corp → Cathedral Bluffs**

- 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:** Cathedral Bluffs Shale Oil Company → Cathedral Bluffs; 1950-01-01 to 1988-04-17; source msha-controller-operator-history
- **controller_controls_mine:** Occidental Oil Shale Inc Et Al → Cathedral Bluffs; 1950-01-01 to 1988-04-17; source msha-controller-operator-history
- **controller_controls_operator:** Occidental Oil Shale Inc Et Al → Cathedral Bluffs Shale Oil Company; 1950-01-01 to 1988-04-17; source msha-controller-operator-history
- **operator_operates_mine:** Emrx Corp → Cathedral Bluffs; 1988-04-18 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Kofford Kay G → Cathedral Bluffs; 1988-04-18 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Kofford Kay G → Emrx Corp; 1988-04-18 to current/open; source msha-controller-operator-history