# Relationship history for MSHA mine 3402021

Current hierarchy: **Tommy  Caldwell → BLUEBIRD STONE → NAVAJO**

- 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:** Don M  Donaho et al → NAVAJO; 1997-07-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Donaho Stone → NAVAJO; 2006-09-08 to 2012-12-30; source msha-controller-operator-history
- **controller_controls_operator:** Don M  Donaho et al → Donaho Stone; 2006-09-08 to 2012-12-30; source msha-controller-operator-history
- **controller_controls_mine:** Tommy  Caldwell  et al → NAVAJO; 2007-12-19 to 2016-01-31; source msha-controller-operator-history
- **controller_controls_mine:** Don M  Donaho et al → NAVAJO; 2011-03-11 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Donaho Stone LLC → NAVAJO; 2012-12-31 to 2018-01-14; source msha-controller-operator-history
- **controller_controls_operator:** Don M  Donaho et al → Donaho Stone LLC; 2012-12-31 to 2018-01-14; source msha-controller-operator-history
- **controller_controls_mine:** Tommy  Caldwell → NAVAJO; 2016-02-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** BLUEBIRD STONE → NAVAJO; 2018-01-15 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Tommy  Caldwell  et al → BLUEBIRD STONE; 2018-01-15 to 2016-01-31; source msha-controller-operator-history
- **controller_controls_operator:** Danny  Caldwell  et al → BLUEBIRD STONE; 2018-01-15 to 2016-01-31; source msha-controller-operator-history
- **controller_controls_operator:** Tommy  Caldwell → BLUEBIRD STONE; 2018-01-15 to current/open; source msha-controller-operator-history