# Relationship history for MSHA mine 1900874

Current hierarchy: **John J  Cronin; Jeremiah B  Cronin → J J Cronin Company → Groton 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:** J J Cronin Company → Groton Pit; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** John J  Cronin  et al → Groton Pit; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** John J  Cronin  et al → J J Cronin Company; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Jeremiah B  Cronin  et al → J J Cronin Company; 1950-01-01 to current/open; source msha-controller-operator-history