Santa Clarita had the highest hotel room occupancy rates in Los Angeles County during the month of May, according to a new study by the hospitality firm PKF Consulting. Hotels in Santa Clarita registered an occupancy rate of 87.22 percent, a 5.3 percent increase from last year and 13 percent higher than the countywide average. Room cost also increased to $121.69, up 8.6 percent from a year prior. In the Valley, room costs increased 11.7 percent to $127.72 on a typical night. Occupancy rates also improved, by 5.1 percent, to 80.53 percent. The Valley gains are still slightly behind the area wide averages for the month. Across the Los Angeles County, rooms averaged $151.63, up 12.6 percent from 2005, and average occupancy was 79.16 percent. The costliest rooms remain in Santa Monica, where an average hotel stay cost $258.33 a night.