# Relationship history for MSHA mine 4607288

Current hierarchy: **Bruce W  Sigler → Double S Mining Inc → Barbara Lynn #1**

- 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:** Hill Michael J → Barbara Lynn #1; 1978-10-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Bruce W  Sigler → Barbara Lynn #1; 1987-02-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Hill Enterprises Inc → Barbara Lynn #1; 1987-04-01 to 1989-08-14; source msha-controller-operator-history
- **controller_controls_operator:** Hill Michael J → Hill Enterprises Inc; 1987-04-01 to 1989-08-14; source msha-controller-operator-history
- **controller_controls_mine:** Maynard Don → Barbara Lynn #1; 1988-10-03 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** C M Brier Corp → Barbara Lynn #1; 1989-08-15 to 1990-11-18; source msha-controller-operator-history
- **controller_controls_operator:** Maynard Don → C M Brier Corp; 1989-08-15 to 1990-11-18; source msha-controller-operator-history
- **operator_operates_mine:** Double S Mining Inc → Barbara Lynn #1; 1990-11-19 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Bruce W  Sigler → Double S Mining Inc; 1990-11-19 to current/open; source msha-controller-operator-history