South Dakota's largest city, Sioux Falls is a vibrant, happening place these days with a historic downtown that attracts visitors and locals in large numbers. Take a walk along South Philips Avenue and the neighboring streets and you'll come across a sculpture walk, cool bars, an excellent choice of restaurants, coffee shops and bakeries, and a whole range of independent stores.
If you go:
While the downtown area is eminently walkable, tickets for the Downtown Sioux Falls Trolley costs only $1 a day (kids 5 and under go free) and the route goes all the way to Falls Park.
Links:

Downtown Sioux Falls, Inc.
230 S. Phillips Ave., Ste 102
Sioux Falls, South Dakota 57104 USA
Phone Numbers:
Downtown Sioux Falls, Inc
+1 (605) 338-4009
+1 (605) 338-4009
Sioux Falls CVB
+1 (605) 275-6060
+1 (605) 275-6060