# Relationship history for MSHA mine 3303508

Current hierarchy: **Williams Thomas M → Jefferson Holding Inc → Elkhorn Strip**

- 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:** Jefferson Holding Inc → Elkhorn Strip; 1975-03-01 to 1978-12-31; source msha-controller-operator-history
- **controller_controls_mine:** Dillon Sherman Atwell → Elkhorn Strip; 1975-03-01 to 1978-12-31; source msha-controller-operator-history
- **controller_controls_operator:** Dillon Sherman Atwell → Jefferson Holding Inc; 1975-03-01 to 1978-12-31; source msha-controller-operator-history
- **operator_operates_mine:** Jefferson Holding Inc → Elkhorn Strip; 1979-01-01 to 1979-08-31; source msha-controller-operator-history
- **controller_controls_mine:** Morrison Jack → Elkhorn Strip; 1979-01-01 to 1979-08-31; source msha-controller-operator-history
- **controller_controls_operator:** Morrison Jack → Jefferson Holding Inc; 1979-01-01 to 1979-08-31; source msha-controller-operator-history
- **operator_operates_mine:** Jefferson Holding Inc → Elkhorn Strip; 1979-09-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Williams Thomas M → Elkhorn Strip; 1979-09-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Williams Thomas M → Jefferson Holding Inc; 1979-09-01 to current/open; source msha-controller-operator-history