"They tumble out of the sky like maple leaves, side-slipping right and left to lose altitude, feet spraddled toward shouts of welcome below." <P>Aldo Leopold could easily have been describing the more than 40,000 geese that punctuate the quiet beauty of the 8,200-acre Washita National Wildlife Refuge each winter. Within the refuge, the slow-moving Washita River winds through prairie and farmlands to merge with Foss Reservoir, providing a home and resting area for geese and other waterfowl. Gently rolling hills, ravines, and bottomlands laced with creeks shelter wildlife as common as white-tailed deer and as exotic as the Texas horned lizard, a State endangered species. <P>