# Relationship history for MSHA mine 4801591

Current hierarchy: **Steven A  Grosch → P E Grosch Construction Inc → South Flat Pit**

- 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

- **operator_operates_mine:** P E Grosch Construction Inc → South Flat Pit; 2001-04-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Steven A  Grosch → South Flat Pit; 2001-04-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Steven A  Grosch → P E Grosch Construction Inc; 2001-04-01 to current/open; source msha-controller-operator-history