There's no better place for a sculpture show than at the Denver Botanic Gardens, what with all those curving walkways, clearings and water features. And exhibitions director Lisa Eldred has used the grounds to her advantage, mounting one great exhibit after another. The most recent one was Catalyst, devoted to pieces by some of the top contemporary sculptors in Colorado, including James Surls, Linda Fleming and Robert Mangold, along with mid-career masters Emmett Culligan, Kim Dickey, Nancy Lovendahl, Terry Maker, Andy Miller, Patrick Marold, Pard Morrison, Carl Reed and Yoshitomo Saito. All were working in abstract and/or conceptual modes, with nary a bronze cowboy or marble ballerina in sight.