The vast majority of OTR would be protected, as sound recordings have especially convoluted copyright durations. According to the Hirtle chart (http://www.copyright.cornell.edu/public_domain/), no sound recordings will enter the public domain until 15 February 2067.
Hawaii Public Radio was created in 1981.
Public Radio Exchange was created in 2007.
Public Radio Fan was created in 2001.
NPR is the abbreviation for National Public Radio.
Iowa Public Radio was created in 2004.
The characters and basic premise are in the public domain, as is the radio show, but the television show and all materials created after 1948 are controlled by CBS.
No; such a work would be in the public domain and cannot be retroactively registered.
No; Lone Ranger radio shows, television, and more are still protected by copyright. There are also nine registered copyrights related to the Lone Ranger.
Public Radio Fan was created in 2001.
Iowa Public Radio was created in 2004.
NPR is the abbreviation for National Public Radio.
Wyoming Public Radio was created in 1966.
Vermont Public Radio was created in 1977.
Wisconsin Public Radio was created in 1948.
Montana Public Radio was created in 1965.
Northern Public Radio was created in 1954.
Colorado Public Radio was created in 1991.