Ok, I did a quickie and found this-

Is consent of all parties required?
In California, Connecticut, Florida, Illinois, Maryland, Massachusetts, Michigan, Montana, Nevada, New Hampshire, Pennsylvania, and Washington state, YES.

Federal law/federal lands, NO. Consent of all parties is not required in these states- Alabama, Alaska, Arizona, Arkansas, Colorado, Delaware, D.C., Georgia, Hawaii, Idaho, Indiana, Iowa, Kansas, Kentucky, Louisiana, Maine, Minnesota, Mississippi, Missouri, Nebraska, New Jersey, New Mexico, New York, North Carolina, North Dakota, Ohio, Oklahoma, Oregon, Rhode Island, South Carolina, South Dakota, Tennessee, Texas, Utah, Vermont, Virginia, West Virginia, Wisconsin, Wyoming.

In all cases I urge caution. The laws could have changed since I was a reporter last (2001).