Debbie McDonald was happy with her horse but mad at herself over a few early stumbles that kept the United States from getting another equestrian medal.
McDonald, who turns 50 tomorrow, finished fourth in individual dressage, done in by a few early mistakes on her horse Brentina.
"The early problems definitely made me concerned," McDonald said. "My body wasn't working with my brain."
Anky van Grunsven and Salinero won a gold medal in the musical freestyle program. Van Grunsven also won this event at the 2000 Games in Sydney.
"It is unbelievable," van Grunsven said. "I never expected to leave Athens with a gold medal."
Ulla Salzgeber of Germany had been leading to that point on Rusty, but wound up getting silver.
Van Grunsven finished at 79.278 percent, with Salzgeber at 78.833 percent.
Spain's Beatriz Ferrer-Salat on Beauvalais got the bronze at 76.667 percent.
American Robert Dover was sixth at 74.713 percent on Kennedy.
Teammate Guenter Seidel finished 14th overall on Aragon with 71.447 percent.
The United States hasn't won a medal in individual dressage since 1932.