# Relationship history for MSHA mine 3304430

Current hierarchy: **Dale R  Bartley; Mitchell W  Bolin → Bartley & Bolin Inc → Bartley & Bolin Plant #3**

- 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:** Lakeville Sand & Gravel → Bartley & Bolin Plant #3; 1998-09-01 to 2010-06-14; source msha-controller-operator-history
- **controller_controls_mine:** Leonard  Schemrich et al → Bartley & Bolin Plant #3; 1998-09-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Leonard  Schemrich et al → Lakeville Sand & Gravel; 1998-09-01 to 2010-06-14; source msha-controller-operator-history
- **controller_controls_operator:** Bruce  Schemrich et al → Lakeville Sand & Gravel; 1998-09-01 to 2010-06-14; source msha-controller-operator-history
- **controller_controls_mine:** Dale R  Bartley  et al → Bartley & Bolin Plant #3; 2000-04-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Bartley & Bolin Inc → Bartley & Bolin Plant #3; 2010-06-15 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Dale R  Bartley  et al → Bartley & Bolin Inc; 2010-06-15 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Mitchell W  Bolin  et al → Bartley & Bolin Inc; 2010-06-15 to current/open; source msha-controller-operator-history