Updated

As search crews continue to look for two missing people following the devastating mudslide in Washington state, scientists are closely monitoring how the avalanche is affecting federally endangered fish runs.

It's too early to know the slide's long-term effects, but so far scientists are hopeful about the immediate prospects: adult steelhead are spawning in clear waters above the slide area, and typical numbers of baby fish are migrating downstream to the marine waters.

The state Department of Fish and Wildlife's Jenni Whitney says the mudslide is foremost a human tragedy. But they're doing fish monitoring work because people will eventually want to know.

The Stillaguamish River once had legendary runs of wild steelhead. Novelist Zane Grey fished its creeks nearly a century ago and described one as the most beautiful trout water he'd seen.