ABC News' Beth Loyd reports:

A team of  more than 70 people and two teams of rescue dogs narrowed their search today on Mount Rainier for the 66-year-old man who disappeared Saturday while leading a group on a snowshoe hike by focusing on two clues, park officials confirmed to ABC News.

Yong Chun Kim of Tacoma, Wash., was leading hikers in the Paradise region of Mount Rainier National Park when he slipped down a steep slope.

Instead of climbing back up to rejoin the group, Kim continued on to meet the group further down the trail.  When he did not arrive 30 minutes after he radioed the group to tell them he was on his way, the park service launched a search.

Park spokeswoman Lee Taylor told ABC that one of the members of Kim's group went along on Sunday's search and took the team to the point where Kim was last seen.  One of the searchers also on Sunday noticed snowshoe tracks in an area called Steven's Creek, which is where the rescue team is now focusing their search.

The search has been hampered by severe weather conditions, including temperatures as low as 10 degrees and snow and wind that have prevented a helicopter from joining the search. The weather is expected to worsen Tuesday.

"Time is not on your side in a situation like this," Taylor said.  "Every day that goes by, it lessens the chance of finding him alive."

Kim is an experienced snowshoer who visited Mount Rainier nearly every weekend.  He was not equipped to stay overnight in the blizzard conditions, however, and only had enough food to survive the first night, according to Taylor.

"The determining factor is team due diligence," Taylor said, adding that searches such as the one underway for Kim could take as long as a week. "We want to make sure that we've looked everywhere that we can," she said.  "There must be a high level of certainty that we have done everything in our power to find him."

Kim has a son who is at the park waiting for news about his father. "He is understandably quite anxious," Taylor said.

The search for Kim is the second one in Mount Rainier Park in less than two weeks.  A manhunt was launched earlier this month to find Benjamin Colton Barnes, 24, after he shot and killed park ranger Margaret Anderson on New Year's Day.

The body of Barnes, an Iraq war veteran, was found the next day, drowned in a creek after suffering from hypothermia.