At best cellphone and Internet access within Yosemite National Park and Yosemite Valley is less than great. In fact, don’t count on having signal most of the time. Some cell phones get excellent reception while a different model phone from the same carrier gets terrible reception. As for Internet access, it depends where you’re at.
WiFI (wireless internet) is available to all park visitors at Yosemite Lodge in Yosemite Valley for the small fee of $5.95 (prices may change). For your $5.95 you can login 7 times or, if you’re lucky and don’t get disconnected, login for 7 days straight. Access is free for Yosemite Lodge overnight guests.
Access areas include the front desk/lobby, the Mountain Room Lounge, the Cliff Room (the Cliff Room has both wired and wireless access), the Falls Room, and the courtyard.
Internet kiosks are available near the front desk for $1 per three minutes. (Kiosks are limited to child friendly internet access.)
Limited Internet access is also available at the small Mariposa County library branch in Yosemite Valley.
WiFi (wireless Internet) is available only for use by guests staying at The Ahwahnee.