Oregon v. Cargill
Oregon v. Cargill is a 1990 ruling of the Oregon Court of Appeals that the Oregon Constitution's initiative and referendum clause, which allows citizens to place measures on the ballot if enough signatures are collected, by extension also allows signature gatherers to enter shopping malls for this purpose.
In 1989, the Oregon Supreme Court ruled in Lloyd Corporation v. Whiffen that mall owners can place reasonable time, place, and manner restrictions on circulators.
Similar case
In 1981, in the neighboring state of Washington, a conclusion similar to Oregon v. Cargill was reached by the Washington Supreme Court in the case of Alderwood Associations v. Washington Environmental Council.