MANKATO — The Children’s Museum of Southern Minnesota is planning to build a permanent site in Mankato.

Since the museum organized in 2006, it’s had three temporary sites. Executive director Peter Olson says nearly $1.7 million has been pledged so far for the $4 million structure. Olson is asking the city for $250,000 to buy a parcel of land next to the Blue Earth County Library.

Olson has estimated the economic impact of the museum at $5 million annually.