Echo Lake, Coalville, Utah. To get to the jump sight, one must get off at the first rest stop on I-80 west once you see the lake. This rest stop is on the wrong side of the highway divider in relation to the lake. Cross the highway along a foot path that is very visible. Follow the foot path down to the lake. There are several different jump heights, pick and chose wisely. There are a lot boaters that like to check out the jumpers, I suggest asking one to give you the water depth with his depthfinder before attempting too big of a jump.
We drove from Park city, but had trouble finding the place. If you drive from Park City on I-80 east, you can't stop at the correct rest stop since it is on the opposite side of the divider so you have to get off exit 168 and get on the west side. Once you are heading on the I-80 West, it is the first rest stop past exit 168. At that point, I-80 looks like it is going south, but it is still going west in the grand scheme of things. The place is really cool, it has probably about 5 or 6 different jump levels ranging from roughly 10 ft to 100 ft.