From Idaho Falls: head north on I-15, and exit at Roberts. Turn right at the end of the ramp and then left at the Tee. Head north on the old highway until you are nearly to the end of the marsh.
Sunrise at Market Lake, only 15 miles north of Idaho Falls, can be a spectacular event. During the spring season, waterbirds abound. During summer and fall, birds are less prevalent but the sunrise is almost always a treat.