And the situation is made even more dangerous by strong gusty winds and low humidity, raising the risk of fires. The National Weather Service has posted an extreme heat watch that goes into effect Friday afternoon, through Sunday morning, and covers a majority of the areas of Eastern, Central and North Central Montana. Top tourist areas saw major impacts, with Flathead County bringing in $207 million and Gallatin County generating more than $152 million. The report shows occupancy at 92% Friday and Saturday of race weekend, and even reaching 88% on the Thursday before the race. Biologists say brown trout compete with and prey upon other sportfish, threatening the broader Flathead fishery if they become established.