# Relationship history for MSHA mine 0202272

Current hierarchy: **Snyder Donald E → Pantano Sand & Gravel → B & R Pit #4**

- 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:** Snyder Donald E → B & R Pit #4; 1982-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Allen Toby & Bruce Greer → B & R Pit #4; 1984-08-10 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** G & A Sand & Gravel Inc → B & R Pit #4; 1985-09-01 to 1986-04-30; source msha-controller-operator-history
- **controller_controls_operator:** Allen Toby & Bruce Greer → G & A Sand & Gravel Inc; 1985-09-01 to 1986-04-30; source msha-controller-operator-history
- **operator_operates_mine:** Pantano Sand & Gravel → B & R Pit #4; 1986-05-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Snyder Donald E → Pantano Sand & Gravel; 1986-05-01 to current/open; source msha-controller-operator-history