# Relationship history for MSHA mine 3304343

Current hierarchy: **Scott M Zemba → Valley Clay Mining Co. → Valley Clay Mining Co.**

- 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:** Valley Clay Mining Co. → Valley Clay Mining Co.; 1994-10-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Steve R  McCann → Valley Clay Mining Co.; 1994-10-01 to 2017-05-31; source msha-controller-operator-history
- **controller_controls_operator:** Steve R  McCann → Valley Clay Mining Co.; 1994-10-01 to 2017-05-31; source msha-controller-operator-history
- **controller_controls_mine:** Scott M Zemba → Valley Clay Mining Co.; 2017-06-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Scott M Zemba → Valley Clay Mining Co.; 2017-06-01 to current/open; source msha-controller-operator-history