Huntinggpsmaps.com is the way to go. The landowner maps work great on Garmin GPS and I know that a lot of the DOW officers are actually using them as well (at least Colorado).
We have found that fences and signs are sometimes way off the actual property lines. Anyone that has ever built a fence can understand why they just built them in straight lines years ago, but property lines are sometimes far from straight. We were surprised at how much land we were missing for years until we learned the actual boundries and found access to 'hidden' public land.
We have one for CO and plan to get one for WY for this year.
We tend to stray from the beaten path and keeping up with where you are at is PRICLESS info...