The trustee distributing the property (i.e., transferring it to the beneficiaries via deed) should know the basis of the property.
The issue, I believe, that @LeroyButch is addressing is whether the sale (via partition suit) or settlement (via buyout) can somehow be treated as a cash inheritance (e.g., no income tax liability) or otherwise. Clearly, the transaction here must be treated as the sale of a capital asset and not a cash inheritance with the beneficiaries taking the trust's basis in the property distributed.
