# Relationship history for MSHA mine 2102451

Current hierarchy: **Robert H  Schmidgall; David R  Schmidgall → Hancock Concrete Products, LLC → Glenwood 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:** Wayne Lee Excavating → Glenwood Pit; 1950-01-01 to 1992-01-14; source msha-controller-operator-history
- **controller_controls_mine:** Wayne  Lee → Glenwood Pit; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Wayne  Lee → Wayne Lee Excavating; 1950-01-01 to 1992-01-14; source msha-controller-operator-history
- **operator_operates_mine:** Hancock Concrete Products Company Inc → Glenwood Pit; 1992-01-15 to 2009-12-31; source msha-controller-operator-history
- **controller_controls_mine:** Gene  Schmidgall → Glenwood Pit; 1992-01-15 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Gene  Schmidgall → Hancock Concrete Products Company Inc; 1992-01-15 to 2009-12-31; source msha-controller-operator-history
- **operator_operates_mine:** Hancock Concrete Products, LLC → Glenwood Pit; 2010-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Robert H  Schmidgall et al → Glenwood Pit; 2010-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Robert H  Schmidgall et al → Hancock Concrete Products, LLC; 2010-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** David R  Schmidgall et al → Hancock Concrete Products, LLC; 2010-01-01 to current/open; source msha-controller-operator-history