# Relationship history for MSHA mine 3607959

Current hierarchy: **Arthur T Walker Estate → Hays Run Coal Company → Spaces Corner Mine**

- 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:** Jrc Land & Equipment Company → Spaces Corner Mine; 1987-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Hays Run Coal Company → Spaces Corner Mine; 1987-10-01 to 1988-08-31; source msha-controller-operator-history
- **controller_controls_mine:** Arthur T Walker Estate → Spaces Corner Mine; 1987-10-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Arthur T Walker Estate → Hays Run Coal Company; 1987-10-01 to 1988-08-31; source msha-controller-operator-history
- **operator_operates_mine:** Nats Creek Mining Company Inc → Spaces Corner Mine; 1988-09-01 to 1991-06-30; source msha-controller-operator-history
- **controller_controls_operator:** Jrc Land & Equipment Company → Nats Creek Mining Company Inc; 1988-09-01 to 1991-06-30; source msha-controller-operator-history
- **operator_operates_mine:** Hays Run Coal Company → Spaces Corner Mine; 1991-07-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Arthur T Walker Estate → Hays Run Coal Company; 1991-07-01 to current/open; source msha-controller-operator-history