Rocky Mountain National Park Boundary Modification and Land Exchange Act This bill provides for a land donation and a land exchange involving Rocky Mountain National Park in Colorado. The Department of the Interior may acquire, by donation, approximately 40 acres of identified nonfederal land for inclusion in the Rocky Mountain National Park. Interior shall convey specified federal land to the owner of specified nonfederal land if the owner of the nonfederal land offers to exchange the land. The values of the federal and nonfederal land to be exchanged shall be considered to be of equal value. The nonfederal land that is acquired by Interior shall be administered as part of Rocky Mountain National Park.