John "Scott" McAndrews and James Juarez fell into the hole as they tried to clear snow from a fence around a fumarole -- a hole from which hot smoke and gases escape -- on Mammoth Mountain, The Los Angeles Times reported. Charles Walter Rosenthal was killed in a rescue attempt.
The deaths occurred on April 6, three days after a storm dumped 40 inches of snow on the mountain.
The mourners Friday included most of the 70 members of the Mammoth ski patrol, ski patrollers from other areas and relatives and friends of the three men.
America McCallisder, Juarez's aunt, described how happy he was when he moved from San Diego to the mountains.
She ended with his words: "I have different types of friends in the mountains. You have to take care of each other. You have to watch after each other, even when you are asleep."