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 opened with Edward Kienholz's The Beanery, and that's such a controversial piece that I think that brought people right away. It was a room-size work that one walked into. It was a bar with Kienholz-type figures sitting and drinking and talking - all life-size characters in a life-size setting. The exhibition was covered in Time, Newsweek, and Life, so it had huge recognition right away.

The gallery closed its doors in 1971. I could no longer psychologically handle the needs of 12 artists. I cared about all of them, and what was happening with their careers. I'm just not a person who can do that indefinitely. And tax-wise I was concerned because they gallery wasn't making money; it was losing money.

People should go to the works and experience them. Because just having an idea or picture in mind is absolutely not the experience that's necessary. Even just landing in Albuquerque or Salt Lake City or Las Vegas was immediately part of the experience. And then you'd get in a car from the airport and take these very long trips - in Michael Heizer's case, it was three hours by car to get to his work. And then there's walking around and into the piece and seeing it from different angles. The kinetic experience of being a part of it physically was very important 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.

Art wasn't for selling. Actually, we once did have an offer on Double Negative. Things could be sold actually - everything could be for sale. But we had very few buyers. I think it was Michael Heizer who said that the point was to have a bigger canvas, and I've used that expression quite a bit. But I was thinking today that a canvas has boundaries; it has limit to it. And for earthwork, it was the very openness and feeling that there were no boundaries that made it so exciting.

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.