Running your Hawk Eye or Red Robin Nature cam out beyond the 75' cable they come with is easy. It's just a matter of plugging the audio, video, and electrical plugs from the original camera into the corresponding plugs of the extension. You can plug at least five or six extensions -- therefore out to about 400' -- without loss of audio, video, or the night vision. Some users have run it out to 600' with no loss of the infrared night vision, but there are no guarantees beyond 400'. Also remember that there are three connections for every 75' you add -- that's 21 for 500' -- that you must make certain don't become unplugged and are waterproofed.
Although the ideal situation for running the cables from tree to house is encasing it in 1.5+" PVC pipe, this can be very difficult and time consuming. We've test-run cables both on top of the ground, and buried under the duff, in the forest behind our office and have two cameras running 24/7 for 4.5+ years.
If encasing the cables in PVC pipe isn't practical, the easiest way to run it across the lawn is to simply take a spade and make a series of slits in the grass and then poke the cable down an inch or so using a wooden or plastic spatula. Just make certain it is far enough down not to be caught by a lawn mower. Failing this, please refer to the Q&A about how to repair a broken cable.