Firefighters aided by rain have made progress fighting a massive blaze that swept through the California desert into Nevada and is threatening the region’s famous spiky Joshua trees. Fire officials say a brief, heavy downpour Tuesday afternoon helped limit the spread of the York Fire. As of Wednesday morning, it was 30% contained after roaring through California's massive Mojave National Preserve and crossing into Nevada. It's California's largest fire this year. However, experts say the Joshua trees — which grow only in the Mojave Desert — are unlikely to regrow if they are scorched. Firefighters are working to contain the fire without disrupting the fragile ecosystem.