Spatial Coverage
- Africa, Central1
- Alaska1
- Algeria1
- Alleghany County (Va.)1
- Amelia County (Va.)1
- Arkansas River1
- Ashe County (N.C.)1
- Asiatic Russia1
- Balkan Peninsula1
- Banks County (Ga.)1
- Bedford County (Va.)1
- Bell County (Ky.)1
- Bent County (Colo.)1
- Berkeley County (W. Va.)1
- Bland County (Va.)1
- Boise County (Idaho)1
- Boston (Mass.)1
- Boston Metropolitan Area1
- Boston Metropolitan Area (Mass.)1
- Boston Region (Mass.)1
