# Relationship history for MSHA mine 3901590

Current hierarchy: **Nathan  Dawson; Dianne  Dawson → Dawson Construction → Unit #2-Kolman-Portable**

- 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:** Daniel  Dawson et al → Unit #2-Kolman-Portable; 1990-05-01 to 2019-01-14; source msha-controller-operator-history
- **operator_operates_mine:** Dawson Construction → Unit #2-Kolman-Portable; 2012-07-09 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Daniel  Dawson et al → Dawson Construction; 2012-07-09 to 2019-01-14; source msha-controller-operator-history
- **controller_controls_operator:** Randy  Dawson et al → Dawson Construction; 2012-07-09 to 2019-01-14; source msha-controller-operator-history
- **controller_controls_mine:** Nathan  Dawson et al → Unit #2-Kolman-Portable; 2019-01-15 to 2020-09-28; source msha-controller-operator-history
- **controller_controls_operator:** Nathan  Dawson et al → Dawson Construction; 2019-01-15 to 2020-09-28; source msha-controller-operator-history
- **controller_controls_operator:** Daniel  Dawson et al → Dawson Construction; 2019-01-15 to 2020-09-28; source msha-controller-operator-history
- **controller_controls_mine:** Nathan  Dawson et al → Unit #2-Kolman-Portable; 2020-09-29 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Nathan  Dawson et al → Dawson Construction; 2020-09-29 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Dianne  Dawson et al → Dawson Construction; 2020-09-29 to current/open; source msha-controller-operator-history