This question was part of CTV`s trivia on their website during the Olympics:
For the first time women and non-commissioned offers were allowed to compete. Danish dressage rider Lis Hartel was the first women to compete in Olympic equestrian events.
Eleven women competed and Lis Hartel from Sweden won silver despite being paralysed from the knees down due to polio. Liselott Linsenhoff from Germany won bronze in the individual competition. In the team event the all-woman team placed. However, once again the judges were faulted for their nationalistic partiality and two judges were removed by the FEI.
Linsenhoff made history in the 1968 Mexico City Olympics as a member of the gold medal individual dressage team. In the 1972 Munich Olympics Linsenhoff again earned an individual gold and a team silver medal.
The surprise fourth place finish was by the all women American team.
The combined eventing competition was held at Bromont, Quebec about an hour from Montreal. Designed by the late Canadian judge and horsewoman Barbara Kemp, the course received high praise for its challenges, safe jumps and its variety and thoughtful lay out asking technical questions spaced evenly along the route and not all in one place as with some previous Olympic cross-country courses.
Hmmm, not only a woman, but a Canadian was the first to design an Olympic cross country course that was both challenging but also SAFE (well from a x perspective!)