MISSOURI VALLEY, Iowa (AP) — Hundreds of farmers in Iowa and Nebraska are still struggling to remove sand and fill holes gouged by the Missouri River, which swelled last summer with rain and snowmelt and overflowed onto thousands of acres of farmland. While the river flooded parts of Montana, the Dakotas, Kansas and Missouri, the worst damage was in Iowa and Nebraska. Iowa farmer Mason Hansen has been working for months to clear his property, but about 160 acres still look like a desert, with sand piled up to 4 feet high. The U.S. Department of Agriculture has approved more than $20 million in disaster aid to help Iowa and Nebraska farmers with the cost of moving sand, grading land and filling holes. But most farmers say that will cover only part of their costs.