# Relationship history for MSHA mine 1515983

Current hierarchy: **Robert L  Rosencrans → Sturgeon Mining Co., Inc → St. Helens Tipple**

- 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:** Robert L  Rosencrans et al → St. Helens Tipple; 1981-02-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Sturgeon Mining Co., Inc. → St. Helens Tipple; 1987-04-01 to 2012-02-27; source msha-controller-operator-history
- **controller_controls_operator:** Robert L  Rosencrans et al → Sturgeon Mining Co., Inc.; 1987-04-01 to 2012-02-27; source msha-controller-operator-history
- **operator_operates_mine:** Jackson Processing Inc → St. Helens Tipple; 2012-02-28 to 2016-10-31; source msha-controller-operator-history
- **controller_controls_mine:** James Michael  Morris Jr → St. Helens Tipple; 2012-02-28 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** James Michael  Morris Jr → Jackson Processing Inc; 2012-02-28 to 2016-10-31; source msha-controller-operator-history
- **operator_operates_mine:** Sturgeon Mining Co., Inc → St. Helens Tipple; 2016-11-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Robert L  Rosencrans et al → Sturgeon Mining Co., Inc; 2016-11-01 to current/open; source msha-controller-operator-history