# Relationship history for MSHA mine 2902019

Current hierarchy: **Atkinson Guy F Company → Monterey Construction Company → Brantley Dam Project**

- 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:** Midwest Construction Company & Luhr Brothers Inc → Brantley Dam Project; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Atkinson Guy F Company → Brantley Dam Project; 1985-03-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Colaska Production Company → Brantley Dam Project; 1986-08-01 to 1988-04-07; source msha-controller-operator-history
- **controller_controls_operator:** Midwest Construction Company & Luhr Brothers Inc → Colaska Production Company; 1986-08-01 to 1988-04-07; source msha-controller-operator-history
- **operator_operates_mine:** Monterey Construction Company → Brantley Dam Project; 1988-04-08 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Atkinson Guy F Company → Monterey Construction Company; 1988-04-08 to current/open; source msha-controller-operator-history