36 CFR §223.81

In emergency situations where prompt removal of timber included in a sale is essential to avoid deterioration or to minimize the likelihood of the spread of insects, the approving officer may authorize shortening the formal advertising period to not less than 7 days. In other emergency situations, or for timber sold under 36 CFR 223.2 the Regional Forester or Chief may authorize shortening the formal advertising period to not less than 7 days.