The Electronic Code of Federal Regulations (e-CFR) is a regularly updated, editorial compilation of C.F.R. material and Federal Register amendments produced by the National Archives and Records Administration’s Office of the Federal Register (OFR) and the Government Printing Office.
In the United States and other areas under the jurisdiction of the FCC, the rules for amateur radio operation are contained in Part 97 of Title 47 – Telecommunications, of the United States Code of Federal Regulations (CFR).
All hams are required to be familiar and comply with the entire Part 97.
The most up to date version of the amateur radio regulations is available at Electronic Code of Federal Regulations.
ARRL maintains a copy of Part 97 which can be found here.
A PDF version of Part 97 is available here.