The Wallis Annenberg Wildlife Crossing will allow mountain lions, bobcats and other wildlife to travel between the Simi Hills and the Santa Monica Mountains over a 10-lane freeway.

The very first layers of soil were dropped ... any dirt — it’s the crossing’s first real piece of nature. “ It wasn't just a bag of soil you bought from Home Depot.

An ideal soil includes various proportions of clay, sand, humus, water and air. You can smell a good soil! ‘The Real Dirt’ is ... Compacted soil layers can either hold water in (by creating ...

Construction crews began the process of placing the first layers of soil over the Wallis Annenberg Wildlife Crossing on Monday morning. (Al Seib/For The Times) ...