Power raking in Denver
We live in Denver. We use a mulcher lawn mower. Is it wise to power rake? If so, how often?
Jefferson County Colorado
We really recommend core aeration over power raking to improve turf and reduce thatch. Thatch is formed from turfgrass stems and roots which don't break down easily and can accumulate. Grass blades (which are returned to the turf via your mulching mower) are mostly water and break down quickly.
Core aeration can be done a couple times a year. Spring (April) is a good time, as is fall (after Labor Day) in September.
Please see this publication which has a discussion of thatch, power raking and other good lawn care practices: