# Relationship history for MSHA mine 2602342

Current hierarchy: **Mitsubishi Corp → Service Rock Products Corp → Service Rock Products-Coyote Springs**

- Valid-time bounds: inclusive, date granularity
- Null end: open-ended in the upstream history row; not independent proof of present control
- Transaction-time observation: 2026-10-18T09:31:49.615908+00:00

## Valid-time edges

- **controller_controls_mine:** Mitsubishi Corp → Service Rock Products-Coyote Springs; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Cyrus W  Spurlino → Service Rock Products-Coyote Springs; 1990-02-26 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Silver State Materials Corp → Service Rock Products-Coyote Springs; 1998-04-01 to 2001-02-28; source msha-controller-operator-history
- **controller_controls_operator:** Cyrus W  Spurlino → Silver State Materials Corp; 1998-04-01 to 2001-02-28; source msha-controller-operator-history
- **operator_operates_mine:** Coyote Valley Llc → Service Rock Products-Coyote Springs; 2001-03-01 to 2002-03-04; source msha-controller-operator-history
- **controller_controls_mine:** Ryan  Williams → Service Rock Products-Coyote Springs; 2001-03-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Ryan  Williams → Coyote Valley Llc; 2001-03-01 to 2002-03-04; source msha-controller-operator-history
- **operator_operates_mine:** Basin Transport LLC → Service Rock Products-Coyote Springs; 2002-03-05 to 2006-03-23; source msha-controller-operator-history
- **controller_controls_mine:** Matthew  Roylance → Service Rock Products-Coyote Springs; 2002-03-05 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Matthew  Roylance → Basin Transport LLC; 2002-03-05 to 2006-03-23; source msha-controller-operator-history
- **operator_operates_mine:** Service Rock Products Corp → Service Rock Products-Coyote Springs; 2006-03-24 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Mitsubishi Corp → Service Rock Products Corp; 2006-03-24 to current/open; source msha-controller-operator-history