The Cherry Creek Trail is walled on both sides and it runs straight through an urban area, which means that it floods fast and hard.
We got a reminder of that last night, when the Denver Fire Department's swift-water team rescued four people from different points along the creek, as ABC 7 reported.
These weren't simple affairs, either. In at least one case, rescue swimmers had to wade out into the surging creek to retrieve a man.
The creek can obviously rise very quickly, especially in storms as intense as last night's, and flood the paths. It might not look like much, but fast-moving water of any depth can knock out your footing and send you down the creek.
The moral of the story: Get out while you can when a storm comes on.
Check out the video below, filmed this time last year, for an extreme but not unusual look at how bad things can get.