When Mount St. Helens in Washington state erupted on 18 May 1980, the initial explosion blew sideways, creating a nearly 600-square-kilometer blast zone—and what has become a prized ecological research area. Dozens of groups have tracked life’s reemergence there, one lupine and ladybug at a time. Now, many of those research projects may be endangered. Last month, the U.S. Forest Service (USFS), which manages the land, issued a decision to build a road stretching through the heart of the research area to the banks of Spirit Lake, 5 kilometers northeast of the crater. The agency says the road will service a tunnel that drains the lake to prevent a catastrophic flood, a threat to tens of thousands of people in the valley below.