Bring a spotting scope if you have one.  

Migrating waterfowl.

In western Fremont Co. Take the Percival/J-26 exit off I-29, and go east on J-26 (200th St.) for 2.5 miles to 220th Ave., a dirt road. The Sheldon Basin area is about one mile south on 220th, near 210th St. To avoid the dirt road, off I-29 instead go south through Percival two miles, along 195th Ave., to 220th St. Go east on 220th St. a little more than two miles to 220th Ave., and then north one mile. 220th Ave is a Level B service road. Use caution if it looks wet or muddy.