# Relationship history for MSHA mine 1100012

Current hierarchy: **Helm Group Inc → Conmat Inc., dba Helm Materials → Spread 4**

- 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

- **controller_controls_mine:** Helm Group Inc → Spread 4; 1950-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** P L Dillon Limestone Inc → Spread 4; 1950-01-01 to 1998-04-27; source msha-controller-operator-history
- **controller_controls_mine:** Dillon Patrick L → Spread 4; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Dillon Patrick L → P L Dillon Limestone Inc; 1950-01-01 to 1998-04-27; source msha-controller-operator-history
- **operator_operates_mine:** Conmat Inc., dba Helm Materials → Spread 4; 1998-04-28 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Helm Group Inc → Conmat Inc., dba Helm Materials; 1998-04-28 to current/open; source msha-controller-operator-history