The Ribalera gorge is located in the Rialp forrest, where Saint Josemaria and companions found themselves during their crossing of the Pyrenees due to the violent religious persecution. They were on their way to Andorra to re-enter Spain via the free zone.
The expedition had just arrived at the gorge, after walking all night. Without waiting any longer, St. Josemaria chose within that place, protected from the wind, the stones that would suit best for a makeshift altar. He was worried there could be irreverent comments or behaviours because throughout the night he heard some blasphemies (the group was constituted by the guides and other men who were not his companions but also wanting to escape). He announced that he was a priest and that he would celebrate the Mass, and that anyone who wanted was welcome to attend.
There were more than twenty men in the group, and they hadn't been to Mass since July 1936. There was a great expectation. One of the attendees, Antonio Dalmases, a university student who was crossing with another group and that had joined the expedition where St. Josemaria was wrote in his diary: "Today I've been to Mass and it has been with an indescribable exitement. I don't know if this is because of the circumstances (of escaping the Spanish communist zone) or because the priest is a saint".
This picture is from a recent camp with boys from England and Scotland. Mass is being celebrated at the site.
One of his companions was Pedro Casciaro, who tells here what he remembers of the Mass celebrated by Saint Josemaría on 28 November 1937, after an interminable march:
During the previous night’s march we had heard some blasphemies as there were all kinds of people in the group. In addition to twenty or so Catalan men there were also some professional smugglers. Even so the Father wanted everyone to know he was a priest, and he got ready to say
I will never forget that Mass. There was no rock high enough to serve as an altar. But there was a lower one which was flat enough. So the Father had to celebrate the Holy Sacrifice kneeling the whole time. In spite of fatigue and the untoward circumstances, he celebrated Mass with such fervour that we were suffused with his piety and devotion. Two of us had to kneel down as well, on either side of him, to hold down the corporal so that no hosts would blow away. Our guide, half-hidden among the trees, observed it all from a respectful distance.
I especially noticed one particular Catalan lad who heard the Mass with real devotion. He looked like a university student. His name was Antonio Dalmasses, and later we became friends. He wrote in his diary: “A priest who is with us celebrated Mass on a rock kneeling, almost lying, on the ground. He did not say it as priests do in churches. His clear, devout way of saying it went right to the heart. I have never heard Mass said as it was today. I am not sure if it was because of the circumstances or because the priest is a saint.
“Holy Communion was particularly moving. It was difficult to distribute because we could hardly move, even though we were all grouped round the altar. We were all dressed in tatters, exhausted, dishevelled, and with several days’ growth of beard. One person had ripped his trousers and the whole length of his leg was exposed. Our hands were bloodstained from scratches. Our eyes were tearful. But more than anything else, God was there with us.”
Pedro Casciaro, Dream and Your Dreams Will Fall Short, Scepter, 1997, pp. 165-7.
cf: http://josemariaescriva.info/article/i-shall-never-forget-that-mass