The update this morning from Inyo County Sheriff has a little bit more of the group background
"...Likely and his two friends have hiked as a group for approximately 30-years, and as a group have summited Mt. Whitney five times throughout the years."
And more details on the search: "...Sequoia-Kings National Park has provided ground operations to search the area between Trail Crest and the Crab Tree Ranger Station. California Rescue Dog Association (CARDA) has also joined the search and will be bringing in specialized search dogs to assist in the operation."