# Relationship history for MSHA mine 2900173

Current hierarchy: **Hugh E  Harvey → H B Potash LLC → H B Potash**

- 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:** Potash Company Of America → H B Potash; 1950-01-01 to 1985-12-31; source msha-controller-operator-history
- **controller_controls_mine:** Ideal Basic Industries Inc → H B Potash; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Ideal Basic Industries Inc → Potash Company Of America; 1950-01-01 to 1985-12-31; source msha-controller-operator-history
- **operator_operates_mine:** Lundberg Industries Ltd → H B Potash; 1986-01-01 to 1988-06-27; source msha-controller-operator-history
- **controller_controls_mine:** Thomas D  Lundberg et al → H B Potash; 1986-01-01 to 1988-06-27; source msha-controller-operator-history
- **controller_controls_operator:** Thomas D  Lundberg et al → Lundberg Industries Ltd; 1986-01-01 to 1988-06-27; source msha-controller-operator-history
- **operator_operates_mine:** Eddy Potash Inc → H B Potash; 1988-06-28 to 1996-08-15; source msha-controller-operator-history
- **controller_controls_mine:** Trans-Resources Inc → H B Potash; 1988-06-28 to 1996-08-15; source msha-controller-operator-history
- **controller_controls_operator:** Trans-Resources Inc → Eddy Potash Inc; 1988-06-28 to 1996-08-15; source msha-controller-operator-history
- **operator_operates_mine:** Eddy Potash Inc → H B Potash; 1996-08-16 to 2004-02-29; source msha-controller-operator-history
- **controller_controls_mine:** Mississippi Chemical Corp → H B Potash; 1996-08-16 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Mississippi Chemical Corp → Eddy Potash Inc; 1996-08-16 to 2004-02-29; source msha-controller-operator-history
- **operator_operates_mine:** H B Potash LLC → H B Potash; 2004-03-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Hugh E  Harvey et al → H B Potash; 2004-03-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Hugh E  Harvey et al → H B Potash LLC; 2004-03-01 to current/open; source msha-controller-operator-history