# Relationship history for MSHA mine 0401854

Current hierarchy: **Robar Enterprises Inc → HI-GRADE MATERIALS CO. → HJ HOVE**

- 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

- **controller_controls_mine:** Granite Construction Inc → HJ HOVE; 1950-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Massey Sand & Rock Company → HJ HOVE; 1950-01-01 to 1986-12-26; source msha-controller-operator-history
- **controller_controls_mine:** Ellis Transportation → HJ HOVE; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Ellis Transportation → Massey Sand & Rock Company; 1950-01-01 to 1986-12-26; source msha-controller-operator-history
- **controller_controls_mine:** Robar Enterprises Inc → HJ HOVE; 1950-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Tarmac California Inc → HJ HOVE; 1986-12-27 to 1992-06-21; source msha-controller-operator-history
- **controller_controls_mine:** Tarmac Plc → HJ HOVE; 1986-12-27 to 1992-06-21; source msha-controller-operator-history
- **controller_controls_operator:** Tarmac Plc → Tarmac California Inc; 1986-12-27 to 1992-06-21; source msha-controller-operator-history
- **operator_operates_mine:** Granite Construction Company → HJ HOVE; 1992-06-22 to 2017-01-02; source msha-controller-operator-history
- **controller_controls_operator:** Granite Construction Inc → Granite Construction Company; 1992-06-22 to 2017-01-02; source msha-controller-operator-history
- **operator_operates_mine:** Hi-Grade Materials Co. → HJ HOVE; 2017-01-03 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Robar Enterprises Inc → Hi-Grade Materials Co.; 2017-01-03 to current/open; source msha-controller-operator-history