36 CFR §17.7

On any property which has been in Federal ownership less than two years, the Secretary, in addition to the notice specified in § 17.4, shall inform the last owner or owners of record by certified mail at their present or last known address of the highest bid on the interest and advise them of their right to acquire the interest for an amount equal to the highest bid if within 30 days they notify the Secretary of their desire to do so and make payment or agree to make payment of an amount equal to that specified in § 17.5.