I think the four land artists I showed all worked within a few years of each other. And they were standard bearers, I suppose, for land art. They each did very separate things. Apparently, later in California, a lot of artists started working in that medium and there was something of a rush of earthworks. But I wasn't involved with that.

What's happening in the larger world always influences art. When I first started the gallery in 1959, one of the first things I learned was that most people assume artists know one thing and one thing only - that they were idiot savants. I found very quickly that most artists were very informed and very aware of what was happening in the world around them. So all of those things go together, especially for earthworks. And at that time there was such an intense interest in American art. So there was a great deal of attention paid to where it was going.

Had opened a gallery I already had strong connections with New York, because I was taking work on consignment from New York dealers. So I already knew a great many of the dealers and the artists here. It wasn't cold for me.

There's a definite connection in terms of objects at hand - dealing with objects or material at hand. Pop art was very much enamored with popular imagery, and popular imagery was of course available and at hand. And land art was also using what was at hand.

I enjoyed cross-country road trips. And I found the work challenging because it was art that existed on the land rather than mere concepts in a gallery or photographic documentation, or any of the paraphernalia that can be used to indicate that. The art was on the land.

I think that Walter De Maria's Lightning Field, Michael Heizer's City, and Charles Ross's work in Star Axis New Mexico , all three will last for a millennium.

I think Michael Heizer and Walter De Maria had a love-hate relationship because they both had a lot in common. But inevitably one would get more publicity than another. Of course, Robert Smithson's gotten so much attention through the years. One of the reasons is not only that his work is quite wonderful, but the fact that he was a writer himself.