Gale Norton is Sec of Interior. She also worked for Reagan.
Alan Fitzsimmons presently works at Interior. He also served Reagan and the elder Bush.
Lynne Scarlett is in #2 position at Interior. Karl Hess serves as her consultant.
James Ziglar was head of INS.
Stuart Anderson is Director of Policy at INS. He also served then Senator Spencer Abraham.
Andrew Biggs served on Bush's SS Commission and as Bush's rep at a UN meeting on aging and retirement. He also serves on the House Banking Committee.
I am confident that many other libertarians work and/or worked for Repubs. Only the names of people in key positions make it into the media.