# Relationship history for MSHA mine 1201258

Current hierarchy: **Chase  Niblock; Chad  Niblock → Niblock Excavating Inc → L-Bob Gravel**

- Valid-time bounds: inclusive, date granularity
- Null end: open-ended in the upstream history row; not independent proof of present control
- Transaction-time observation: 2026-10-17T05:35:58.500035+00:00

## Valid-time edges

- **controller_controls_mine:** Rieth-Riley Construction Company Inc → L-Bob Gravel; 1950-01-01 to 2025-01-30; source msha-controller-operator-history
- **operator_operates_mine:** L-Bob Gravel → L-Bob Gravel; 1950-01-01 to 1980-03-31; source msha-controller-operator-history
- **controller_controls_mine:** Bob  Ernsberger → L-Bob Gravel; 1950-01-01 to 1987-06-15; source msha-controller-operator-history
- **controller_controls_operator:** Bob  Ernsberger → L-Bob Gravel; 1950-01-01 to 1980-03-31; source msha-controller-operator-history
- **operator_operates_mine:** Rieth-Riley Construction Company Inc → L-Bob Gravel; 1980-04-01 to 1984-05-29; source msha-controller-operator-history
- **controller_controls_operator:** Rieth-Riley Construction Company Inc → Rieth-Riley Construction Company Inc; 1980-04-01 to 1984-05-29; source msha-controller-operator-history
- **operator_operates_mine:** L-Bob Gravel → L-Bob Gravel; 1984-05-30 to 1987-06-15; source msha-controller-operator-history
- **controller_controls_operator:** Bob  Ernsberger → L-Bob Gravel; 1984-05-30 to 1987-06-15; source msha-controller-operator-history
- **operator_operates_mine:** Niblock Excavating Inc → L-Bob Gravel; 1987-06-16 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Gary  Niblock → L-Bob Gravel; 1987-06-16 to 2019-03-31; source msha-controller-operator-history
- **controller_controls_operator:** Gary  Niblock → Niblock Excavating Inc; 1987-06-16 to 2019-03-31; source msha-controller-operator-history
- **controller_controls_mine:** Chase  Niblock et al → L-Bob Gravel; 2019-04-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Chase  Niblock et al → Niblock Excavating Inc; 2019-04-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Chad  Niblock et al → Niblock Excavating Inc; 2019-04-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** RR Holdco, Inc. → L-Bob Gravel; 2025-01-31 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** RR Holdco, Inc. → Rieth-Riley Construction Company Inc; 2025-01-31 to 1984-05-29; source msha-controller-operator-history