A 1-meter-long wooden ruler and a 20-meter-long tape measure were all he had. In the daytime, he and his colleague measured the carvings; at night, he drew the pictures on a large piece of paper under the kerosene lamp in his cottage.
"My nose was filled with black stuff from the burning kerosene," he says.
After three years of hard work, Guo completed a 23.15-meter-long scroll of all the major stone statues on Mount Baoding and Mount Beishan.
Thanks to his contributions to rock carving, Guo was selected as a deputy county head in charge of culture and tourism in 1984, which gave him an idea to promote Dazu Rock Carvings to the world by applying for the UNESCO World Heritage Site.
In the 1980s, China had only five UNESCO World Heritage sites, including the Forbidden City in Beijing and the Mogao Caves in Dunhuang, Gansu province.
The preparations for the application took years. In 1990, Guo quit as deputy county head after serving two terms and founded Dazu Rock Carvings Museum, a major step on the road to the UNESCO list.