# Relationship history for MSHA mine 0202543

Current hierarchy: **Ivan J  Smith; Robert J  Bell → Smith & Bell Construction Company → Graham 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:** Smith & Bell Construction Company → Graham Pit; 1990-11-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Ivan J  Smith Et Al → Graham Pit; 1990-11-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Ivan J  Smith Et Al → Smith & Bell Construction Company; 1990-11-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Robert J  Bell Et Al → Smith & Bell Construction Company; 1990-11-01 to current/open; source msha-controller-operator-history