It's a cedar (Cedrus). There's nothing about the roots that is particularly distinctive or noteworthy - like pretty much all trees other than desert species the majority of the roots will be near the surface. As with all evergreen conifers the area within the canopy will be dry and covered in old needles, not too great for gardening.

@Embothrium I am reading that cedars have roots at six to seven feet. Contrast this against Coastal Redwoods around five to six feet. You would think in both cases that the roots would just cruise right under patios and foundations without creating a lot of disturbance. This is assuming that the tree was planted a proper distance from a home (probably 50 feet).

When a Conifer root is over a garden area that gets a lot of water, does the root try to grow up into the top soil layer? Or does the root just stay down at five+ feet and wait for gravity to send the water down?

And it completely depends on what type of soil and where the water is. I have a beech tree that I planted as a #15 in a spot that had been a gravel driveway. I moved it 10 years after planting, during which time it had barely doubled in size, only to discover that the compacted gravel beneath it meant that the root mass was less than a foot deep. I moved it to good soil and five years later it was about 10 times the size it had been when moved. Same deal with a Cedrus atlantica 'Glauca Pendula' that had been planted in a raised bed next to a parking lot at a local nursery. It was scratching customers' cars so they told me that if I could get it out, I could have it. The root 'ball' resembled a tortilla! And the tree was reasonably healthy and attractive. I saw the root mass and figured that there was no way that the tree would survive the transplanting. Today, 10 years or so later, it is magnificent. One of the reasons that I go through the exercise of moving trees rather than just eliminating them is that it is a great way to examine what is going on unseen...

I have had no problem gardening around cedars (and I have a lot of them). Totally different than redwoods. The only thing that you can put under a redwood is mulch.

There's around and then there is directly beneath.

@Sara_Malone You should work as a tree transplant consultant, maybe offering your services remotely since video conferencing is becoming so easy. That is valuable experience you have.

@gardengal48 Okay, So the Redwood tree and the Cedar are both still in the running as culprits. I am going by online resources that claimed that most of the Redwood's main roots are at five to six feet and Cedar at six to seven feet. Obviously that was a simplification.

I still have not heard a clear answer to this question: When a Conifer root is over a garden area that gets a lot of water, does the root try to grow up into the top soil layer? Or does the root just stay down at its normal level and wait for gravity to send the water down?

If these roots grow up to the source, then it would not matter that they usually grow deep.

The redwood will go anywhere for water, even into a pot with moist soil sitting on the ground. The cedar is unlikely to do that. But as we've said, it depends on several factors.

"I still have not heard a clear answer to this question: When a Conifer root is over a garden area that gets a lot of water, does the root try to grow up into the top soil layer? Or does the root just stay down at its normal level and wait for gravity to send the water down?"

But you did get your answer!! A tree's feeder roots - those that provide it with nearly all of its moisture and nutrient accessing ability - are located just below the soil surface = "top soil level".

And it is rare for tree roots to ever go very deep. Most grow like an extended pancake with a slightly pointy center :-) Even trees with tap roots lose them over the course of time and it is usually only trees that grow in very arid climates that have roots that penetrate into the soil very deeply