Forest Improvements through Research and Emergency Stewardship for Healthy Ecosystem Development and Sustainability Act or the FIRESHEDS Act This bill directs the Department of Agriculture (USDA), with respect to National Forest System lands, and the Department of the Interior, with respect to public lands, no later than 90 days after receiving a request from a state, to enter into an agreement with such state to jointly designate one or more fireshed management areas within such state, and conduct fireshed management projects in such fireshed management areas. Not later than 90 days after entering into an agreement, the USDA or Interior, as appropriate, and such state shall jointly conduct a stewardship and fireshed assessment. The USDA and Interior shall carry out fireshed management projects in accordance with the timeline and project size limitations included in the stewardship and fireshed assessment. Fireshed management projects shall be categorically excluded from the preparation of an environmental assessment or an environmental impact statement and exempt from the special administrative review process.