The principal appraiser, Caroline Seigel, is an Accredited Member of the American Society of Appraisers. She earned a Certificate in Appraisal Studies from George Washington University for having completed the four core appraisal courses offered by ASA, as well as courses in conoisseurship of fine and decorative art. These ASA core courses cover appraisal methodology, research, report writing, and valuation law. She has been tested and practices in accordance with the Uniform Standards of Professional Appraisal Practice, or USPAP, as stated by the Appraisal Foundation in Washington, D.C. She is currently an officer of the New Mexico Chapter of the American Society of Appraisers, and has eight years of full-time art appraisal experience. She founded her practice, 20th C. West Art Appraisal in 2004. Prior to starting her business, Seigel worked for three years with Bernard Ewell Art Appraisals, Santa Fe. Seigel is recognized as an expert witness in art appraisal in New Mexico and Colorado.

Seigel earned a B.A. in Studio Art from Colorado College, Colorado Springs; a M.A. in Art History from Indiana University, Bloomington; and a M.L.S. (Masters in Library Science) also from Indiana University. She is currently enrolled in the University of New Mexico School of Law, where she is pursuing a J.D.

Seigel has expertise in American paintings, sculpture and works on paper, with a specialization in Western and Southwestern fine art. She has appraised high-value fine art by members of the Taos Society of Artists and by New York Modernists for donation to the New Mexico Museum of Art and to the Georgia Keeffe Museum, both Santa Fe, as well as for insurance and estate settlement of private collections. Other professional projects include researching and writing bibliographies of sculptors represented in the Frederick Meijer Sculpture Gardens in Grand Rapids, Michigan.20th Century West Art Appraisal is a member of the Business Council of the New Mexico Museum of Art, and a Better Business Bureau Accredited Business.