Horse and man alike respond poorly to force.
"For what a horse does under constraint, as Simon says, he does without understanding, and with no more grace than a dancer would show if he was whipped and goaded. Under such treatment horse and man alike will do much more that is ugly than graceful. No, a horse must make the most graceful and brilliant appearance in all respects of his own will with the help of aids."
It took me a very long time to try out Gracie on the steeper ridge trails around our place, as I was hesitant to take a youngster atop some of our more rugged ridges without a seasoned horse to follow, and timing never worked out for a buddy to ride with. But this week I decided that Gracie and I are ready for solo steep climbs and narrow ridge tops.
Gracie honestly gives all she's got on the steepest climbs, is oh-so-careful walking along the tops of the ridges, and slowly picks her way in a collected and balanced manner down steep hills. -- Gracie's a ridge walker now :) and she loves the sweet view from the top as much as I do :-D