# Relationship history for MSHA mine 4503524

Current hierarchy: **Danny L  Simpson Sr. → SSG Mineral Resources & Recycling, Inc. → Simpson 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:** Kayak Crest Aggregates → Simpson Pit; 2002-12-19 to 2007-08-08; source msha-controller-operator-history
- **controller_controls_mine:** Danny L  Simpson Sr. → Simpson Pit; 2002-12-19 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Danny L  Simpson Sr. → Kayak Crest Aggregates; 2002-12-19 to 2007-08-08; source msha-controller-operator-history
- **operator_operates_mine:** Simpson Sand & Gravel → Simpson Pit; 2007-08-09 to 2017-02-28; source msha-controller-operator-history
- **controller_controls_mine:** Dan L  Simpson Jr. → Simpson Pit; 2007-08-09 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Dan L  Simpson Jr. → Simpson Sand & Gravel; 2007-08-09 to 2017-02-28; source msha-controller-operator-history
- **operator_operates_mine:** SSG Mineral Resources & Recycling, Inc. → Simpson Pit; 2017-03-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Danny L  Simpson Sr. → Simpson Pit; 2017-03-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Danny L  Simpson Sr. → SSG Mineral Resources & Recycling, Inc.; 2017-03-01 to current/open; source msha-controller-operator-history