Oregon Revised Statutes Public Health and Safety § 433.735

(1) “Outdoor mass gathering,” unless otherwise defined by county ordinance, means an actual or reasonably anticipated assembly of more than 3,000 persons which continues or can reasonably be expected to continue for more than 24 consecutive hours but less than 120 hours within any three-month period and which is held primarily in open spaces and not in any permanent structure.

(2) “Organizer” includes any person who holds, stages or sponsors an outdoor mass gathering and the owner, lessee or possessor of the real property upon which the outdoor mass gathering is to take place.

(3) “Permanent structure” includes a stadium, an arena, an auditorium, a coliseum, a fairgrounds or other similar established places for assemblies.

(4) “Temporary structure” includes tents, trailers, chemical toilet facilities and other structures customarily erected or sited for temporary use.