# Relationship history for MSHA mine 3003977

Current hierarchy: **Dave  Burrell → Burrell's Excavating, Inc. → Sandvik QA440 Serial 1886SW13168**

- Valid-time bounds: inclusive, date granularity
- Null end: open-ended in the upstream history row; not independent proof of present control
- Transaction-time observation: 2026-10-17T05:35:58.500035+00:00

## Valid-time edges

- **controller_controls_mine:** Dave  Burrell  et al → Sandvik QA440 Serial 1886SW13168; 1999-04-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Burrell's Excavating, Inc. → Sandvik QA440 Serial 1886SW13168; 2016-05-19 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Dave  Burrell  et al → Burrell's Excavating, Inc.; 2016-05-19 to current/open; source msha-controller-operator-history