Sluicing on the Purgatory River, Colorado

[TheNewCatfish]

Planning a trip to the Purgatory to do some prospecting. But the Purgatory River is vast covering almost 200 miles. Can anyone help me focus on what parts of the Purgatory might offer the best access and panning sites ? Are there public lands anywhere along the river that allow panning or sluicing ? What towns are closest to these areas ?