# Relationship history for MSHA mine 0404898

Current hierarchy: **Rusty  Risi → GPS River Rock Products Co → GPS River Rock Products Co**

- Valid-time bounds: inclusive, date granularity
- Null end: open-ended in the upstream history row; not independent proof of present control
- Transaction-time observation: 2026-10-17T05:35:58.500035+00:00

## Valid-time edges

- **operator_operates_mine:** Southwest Ready Mix Inc → GPS River Rock Products Co; 1987-09-01 to 2002-06-14; source msha-controller-operator-history
- **controller_controls_mine:** Charles E  Beard et al → GPS River Rock Products Co; 1987-09-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Charles E  Beard et al → Southwest Ready Mix Inc; 1987-09-01 to 2002-06-14; source msha-controller-operator-history
- **operator_operates_mine:** GPS River Rock Products Co → GPS River Rock Products Co; 2002-06-15 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Charles E  Beard et al → GPS River Rock Products Co; 2002-06-15 to 2017-03-31; source msha-controller-operator-history
- **controller_controls_operator:** Charles E  Beard et al → GPS River Rock Products Co; 2002-06-15 to 2017-03-31; source msha-controller-operator-history
- **controller_controls_mine:** Rusty  Risi → GPS River Rock Products Co; 2017-04-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Rusty  Risi → GPS River Rock Products Co; 2017-04-01 to current/open; source msha-controller-operator-history