A flock of 12 willets fed in shallow waters.

At the northwest corner of Lake  Ladora at the Rocky Mountain Arsenal National Wildlife Refuge, the shoreline consists of mudflats and a shallow beach surrounded by cattails.

Top: Lesser yellowlegs. Bottom: Killdeer.

Shorebirds in their spring breeding plumages from the southern and coastal United States and Central and South America stop to rest and refuel as they rush north as far as Alaska and the Arctic tundra to breed. Like clockwork, their transient appearance is predictable in land-locked Colorado.

Semipalmated sandpiper.

Eleven different shorebirds visited the same patch of habitat on Lake Ladora during spring migration. The importance of these stopovers is critical to the shorebirds’ survival. Come fall migration, they will pass through again. Be on the lookout for shorebirds from August to October.

Semipalmated plover.

Bird Walks: Aug. 1 and Sept. 5. Two start times: 7:30am and 8am. Walks are free, but you must RSVP at  blufflake.org/birdwatching. All are welcome. Bring  your own binoculars or  borrow a pair from your guide. 11255 MLK Jr. Blvd.

Least sandpipers.