Burial or spreading of ashes, outside established cemeteries, might be permitted by whoever manages or governs the land. This may be a city, county, national park service, federal bureau of land management, etc. It is important to check with the managing or governing entity before disposing of remains.
Embalming is not required if disposal is within 24 hours. A dead human body or fetus kept more than 24 hours before burial or cremation must be embalmed or properly refrigerated. Transport of remains may be in a container that is tightly sealed to prevent the leakage of fluids or odor.