# Relationship history for MSHA mine 2500321

Current hierarchy: **Timothy L  Stalp → Stalp Gravel Inc → Wisner 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

- **operator_operates_mine:** Stalp Gravel Co → Wisner Plant; 1950-01-01 to 2006-03-31; source msha-controller-operator-history
- **controller_controls_mine:** Henry A  Stalp → Wisner Plant; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Henry A  Stalp → Stalp Gravel Co; 1950-01-01 to 2006-03-31; source msha-controller-operator-history
- **operator_operates_mine:** Stalp Gravel Inc → Wisner Plant; 2006-04-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Timothy L  Stalp → Wisner Plant; 2006-04-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Timothy L  Stalp → Stalp Gravel Inc; 2006-04-01 to current/open; source msha-controller-operator-history