# Relationship history for MSHA mine 0404163

Current hierarchy: **RRM Development Corporation; Mitsubishi Corp → Robertson's Ready Mix Ltd → Ridgecrest Rock Plant**

- 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 → Ridgecrest Rock Plant; 1950-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Cal-Ci-Co Rock Company Inc → Ridgecrest Rock Plant; 1950-01-01 to 2001-03-11; source msha-controller-operator-history
- **controller_controls_mine:** Wallace K  Love  et al → Ridgecrest Rock Plant; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Wallace K  Love  et al → Cal-Ci-Co Rock Company Inc; 1950-01-01 to 2001-03-11; source msha-controller-operator-history
- **controller_controls_operator:** Chris E  Babcock  et al → Cal-Ci-Co Rock Company Inc; 1950-01-01 to 2001-03-11; source msha-controller-operator-history
- **controller_controls_mine:** Mitsubishi Corp  et al → Ridgecrest Rock Plant; 1995-10-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Granite Construction Company → Ridgecrest Rock Plant; 2001-03-12 to 2022-05-22; source msha-controller-operator-history
- **controller_controls_operator:** Granite Construction Inc → Granite Construction Company; 2001-03-12 to 2022-05-22; source msha-controller-operator-history
- **operator_operates_mine:** Robertson's Ready Mix Ltd → Ridgecrest Rock Plant; 2022-05-23 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Mitsubishi Corp  et al → Robertson's Ready Mix Ltd; 2022-05-23 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** RRM Development Corporation et al → Robertson's Ready Mix Ltd; 2022-05-23 to current/open; source msha-controller-operator-history