43 C.F.R. § 3515.25
Is BLM required to publish notice or hold a hearing?
Yes. After you and BLM agree on the lands for exchange, we will publish a notice of the proposed exchange in the
(a) The time and place of a public hearing(s);
(b) Our preliminary findings that the exchange is in the public interest; and
(c) A request for public comments on the merits of the proposed exchange.