There are seemingly only three entrances to the “277 mile” span of the Grand Canyon:
According to nps.gov, The “North Rim” (36.198556, -112.052596) is Closed for the winter and is open from “May 15th through October 15th of each year”.
The “South Rim” is open year-round. The admission is $30 although this is not advertised on billboards.
The Grand Canyon glass “Skywalk” is privately owned and costs $41 per adult.