| Location | Age (years BP) | Reference |
|---|---|---|
| Within modern distribution | ||
| Isanti Co., MN | 10,000-11,000 | Cushing 1964 |
| Stevens Pond, MN | Holocene Epoch (trace) | Janssen 1967 |
| Koochiching Co., MN | 9,000 | Janssen 1968, 1973 |
| Hubbard Co., MN | 5,000 (trace) | McAndrews 1966 |
| western Lake Superior, MN | age ? | Maher 1977 |
| Franklin and Monroe Co., PA | 11,000-13,000 | Watts 1980 |
| Outside modern distribution | ||
| northwest GA | Pleistocene Epoch | Watts 1970, 1973, 1975 |
| Lincoln Co., IN | age ? (1% pollen) | Whitehead and others 1982 |
| NC | 40,000 (1% pollen) | Whitehead 1963, 1964, 1965, 1967, 1981 Whitehead and Barghoorn 1962 Whitehead and Doyle 1969 |
| TN | 20,000 (trace) | Delacourt and others 1980 |
| VI | 10,000 (trace) | Craig 1969 |
| Driftless area, SE WI | age ? | Hartley 1966 |