# Relationship history for MSHA mine 3302359

Current hierarchy: **Ronnie L Welch; James R Welch → Welch Sand & Gravel Inc. → Ross Pit**

- 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:** Charles H  Welch et al → Ross Pit; 1950-01-01 to 2015-12-31; source msha-controller-operator-history
- **operator_operates_mine:** Welch Sand & Gravel Inc. → Ross Pit; 1981-06-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Charles H  Welch et al → Welch Sand & Gravel Inc.; 1981-06-01 to 2015-12-31; source msha-controller-operator-history
- **controller_controls_mine:** James R Welch et al → Ross Pit; 2016-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** James R Welch et al → Welch Sand & Gravel Inc.; 2016-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Ronnie L Welch et al → Welch Sand & Gravel Inc.; 2016-01-01 to current/open; source msha-controller-operator-history