# Relationship history for MSHA mine 1101921

Current hierarchy: **Allen  Hoffman → Bedrock Quarry Products → Hoffman**

- 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:** Doty & Hoffman → Hoffman; 1988-05-01 to 2000-12-31; source msha-controller-operator-history
- **controller_controls_mine:** Doty Wayne & Don Hoffman → Hoffman; 1988-05-01 to 2000-12-31; source msha-controller-operator-history
- **controller_controls_operator:** Doty Wayne & Don Hoffman → Doty & Hoffman; 1988-05-01 to 2000-12-31; source msha-controller-operator-history
- **operator_operates_mine:** Bedrock Quarry Products → Hoffman; 2001-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Allen  Hoffman → Hoffman; 2001-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Allen  Hoffman → Bedrock Quarry Products; 2001-01-01 to current/open; source msha-controller-operator-history