A rare and massive ranch near Aspen is for sale for $150 million — but there's a catch. Take a look.

• A monastery compound on over 3,700 acres near Aspen, Colorado, is on the market $150 million. 
• There aren't many monks left, and the land near the ritzy ski town is mostly used as a ranch. 
• This amount of land near Aspen is rare, but there aren't many viable, serious buyers. Here's why.

A 3,720-acre ranch in Snowmass, Colorado — a ski town 15 miles north of Aspen — is on the market for $150 million.

Its current owner is St. Benedict's Monastery, which no longer has enough monks to support itself and is looking for buyers who want a lot of land close to the slopes.

Listing agent Ken Mirr, who specializes in ranches, knows how rare a property like this is.