Boquillas Canyon Professional Review and Guide
"Boquillas means “little mouths” in Spanish. Although no one is sure where the name for the canyon originated, some believe it was named either for the canyon’s narrow entrance or for the numerous small openings, or solution holes, in its limestone walls.
The Boquillas Canyon Trail is a popular short trail, appropriate for adults and children. Be aware, however, that during late spring, summer, and early fall midday temperatures frequently rise above 100°F. During the hot time of year, walks along this trail are best taken in the early-morning hours."