# Relationship history for MSHA mine 4104962

Current hierarchy: **Emilio  Chavez → Volcanic Stone  Co. → Portable Crusher  #1**

- 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:** Harlan R  Getman et al → Portable Crusher  #1; 2010-06-15 to 2022-11-30; source msha-controller-operator-history
- **operator_operates_mine:** Volcanic Stone  Co. → Portable Crusher  #1; 2012-10-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Harlan R  Getman et al → Volcanic Stone  Co.; 2012-10-01 to 2022-11-30; source msha-controller-operator-history
- **controller_controls_operator:** Clarence R  Getman et al → Volcanic Stone  Co.; 2012-10-01 to 2022-11-30; source msha-controller-operator-history
- **controller_controls_mine:** Emilio  Chavez → Portable Crusher  #1; 2022-12-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Emilio  Chavez → Volcanic Stone  Co.; 2022-12-01 to current/open; source msha-controller-operator-history