I took the total number of real estate listing in Washington, Utah, and Salt Lake Counties and calculated the number of listing per 10,000 residents in each county.
Salt Lake County: 18.8 listings/10k
Utah County: 29.4 listings/10k
Washington County: 79.9 listings/10k
I also took the number of listing over $1,000,000 and calculated the number of listings per 10,000 residents, which was even more eye opening.
Salt Lake County: 3.7 listing/10k
Utah County: 4.8 listings/10k
Washington County: 16.0 listings/10k
This data is from July, but I'm sure the current numbers are similar. It looks like Washington County could be in for a considerable correction.