山东省胶州市三里河遗址的发现是1961年。当时在山东大学历史系教书的刘敦愿先生看到了一幅古画，为高凤翰作品的摹本，画中一束鲜荷栽植在一件史前时期的陶里，其旁有一首小诗，其中两句为“田夫掘出说前朝，老夫拾来插瓶供”。陶是远古时代用作烧水或盛水的器具，造形似鸟。刘先生是山大考古专业的奠基人，对山东史前的历史和文物知根知底，画上的陶和题诗引起了他的思索: 高凤翰出身于胶州，病退后回原籍三里河故居生活，田夫掘出的陶应在高凤翰居处附近，莫非那里有一处古代遗址。带着这个猜测，刘先生去胶州进行了考察，果真在那里找到了一处极为重要的史前时期文化遗址。这就是胶州三里河遗址。
遗址在今胶州市城南三里河村前的一块高土台地上，面积约5万平方米。1974年和1975年中国社科院考古研究所联合山东有关文物部门在这里进行了两次考古发掘，共发掘了1500余平方米的面积，出土了大量的史前大汶口和龙山时代的文物，统计的数量多达1200余件；还采集了许多与远古人生活、丧葬有关的重要信息，其中房址5座，墓葬164座。这次发掘的意义在于，首次明确了大汶口文化和龙山文化之间的传承关系。因为在此之前，人们虽然朦胧地意识到大汶口文化有别于龙山文化的迹象，但苦于无明确的可证资料，三里河遗址和与此同时发现的日照东海峪、诸城呈子等遗址，以十分鲜明的地层关系和实物资料，证明了大汶口文化早于龙山文化，龙山文化是由大汶口文化发展而来的，两者关系的明确，把山东地区远古文化的序列串连了起来，郁积多年的历史问题也得以明朗化。
在仅发掘的千余平方米的土层中，可随时发现猪的踪迹。发现的66座大汶口文化墓葬中有18座出土了猪的下颌骨，发现的98座龙山文化墓葬中的19座出土了猪的下颌骨，累积的猪下颌骨数量多达214块。不仅如此，在属于大汶口文化的一个口径只有80厘米的小坑内发现了5头完整的小猪的骨架。
今人和远古人对猪的感情已大不相同。在距今5000年上下的大汶口时期，猪有着某种尊宠的地位，上面提到的埋在坑内的5头小猪和一头大猪，可能蕴涵着一些原始宗教的情感。不仅如此，猪甚至还是财富的象征。在已经发掘的史前墓葬中，我们发现以猪下颌骨或猪头来随葬的不是权贵就是富人，一般平民应该是没有猪的。因为猪是财富，因此其数量越多，主人就越显贵；三里河遗址中，单座墓葬最多的随葬了猪下颌骨37块。在章丘大汶口遗址中，单座墓葬最多的随葬了猪头骨14具。
遗址中还发现一件别致的猪的“雕塑品”，人称陶“猪”，用途与高凤翰作品上的陶一样，只不过在的下部作成猪的模样，形象至极：四肢蜷曲，很惬意地作匍匐状，短尾上翘，俏皮可爱，小耳前扑，稍稍遮挡着眼睛，拱嘴两侧獠牙外露，其憨态可掬。一件普通的生活用品，便看出了三里河人对猪的喜爱之情溢于“言表”。
当然，史前时期的猪，也不是金贵得不能吃。猪的主要作用依然是服务于人的胃口，这也是刺激养猪业发达的动力之一。养猪业的发展，反映了很多的社会问题，最起码的是人们必须有剩余的粮食来圈养猪。三里河遗址里发现了一座装粮食的房子，发掘者很形象地称之为“粮库”，粮食虽然已经炭化，但至今依然保存了1.2个立方米的体积。这些信息告诉我们：5000年前的三里河人早已摆脱了食不果腹的原始状态，过上了安定的农业生活，不但能为自己储存粮食，还有可能给猪分食一部分。人与多数量的猪共享粮食，在远古时代是件了不起的事情。
生活富裕了的人们自然忘不了要追悼一下自己的祖先，希望从祖先们那里为自己祈福，让自己的幸福生活继续下去，于是对祖先和神灵的崇拜发展起来。在三里河遗址中还发现了两处特别引人关注的龙山时期祭祀建筑：一处是长90厘米、宽60厘米的长方形地面，面上用20多块大小均匀的鹅卵石铺成，其旁有一具完整的狗骨架；另一处是一个直径为120厘米的圆坑，坑底部和坑壁经过了精心而复杂的加工，最后还在底部铺了一层鹅卵石。这两处祭祀建筑均挨近某一个或一组墓葬，研究者推测这些建筑原是后人祭祀自己祖先时所用的设施。这似乎让今人找到了祭祖的源头。不过，这些不能说话的“建筑”，并不能让今人解读当时祭祀者的表情和心理，更难以说出他们如此构建的理由，我们只能像天书一样揣测和想象他们的虔诚和祭场的神秘。
The Sanlihe Cultural Relics Site in Jiaozhou City, Shandong Province, was discovered in 1961. At that time, Liu Dunyuan, a professor of the History Department of Shandong University saw an ancient painting, which was a reproduction of Gao Fenghan’s works. In the painting, a fresh lotus was planted in a pre-historic pottery gui. Besides the gui was a poem, which explained that “The farmer who excavated this vessel said it was made during pre-historic times, so I use it to plant lotus.”
The gui has a bird-like shape and is a kind of vessel with three legs used to hold water or cook food in ancient times. Professor Liu, father of the archaeology major at Shandong University, knew much about the pre-historic cultural relics of Shandong Province. So, the painting of the earthenware gui and the poem attracted his attention.
Gao Fenghan was born in Jiaozhou. After he retired from his official post due to illness, he went back to his former residence in Sanlihe. So, the site where the farmer excavated the pottery gui must have been near the residence of Gao Fenghan and could well be a site containing many other cultural relics. Based on this speculation, Mr. Liu went to Jiaozhou for an on-the-spot investigation and thus became the first to discover the Sanlihe Cultural Relics Site.
This SCRS covers an area of 50,000 square meters and is located in a rising earth stage in Sanlihe Village just to the south of the present day Jiaozhou City. In 1974 and 1975, various members from the Archaeology Institute of the Chinese Academy of Social Sciences and the Historic and Cultural Relics Department of Shandong Province undertook archaeological excavations twice at this site. By excavating an area of more than 1500 square meters, more than 1200 fragments of pre-historic cultural relics of the Dawenkou and Longshan periods were unearthed. From the five homes and 164 tombs discovered to date, much important information concerning the residential and burial habits of ancient people was gleaned.
In several layers of excavated earth, traces of pigs were found in abundance. Among 66 tombs that belonged to the Daweniou Culture period, the lower jaw bones of pigs were found in 18 tombs. Among the 98 tombs that belonged to the Longshan Culture period, the lower jaw bones of pigs were found in 19 tombs. Altogether, 214 pieces of lower jaw bones of pigs were discovered. Moreover, in a pit with a width of only 80 centimeters, five entire pig skeletons were discovered.
At this same site, an elegant “pottery sculpture” was also discovered, so it was dubbed the “Pig Gui” by local people. It has the same function as the pottery gui, the only difference being that the lower part of the “Pig Gui” is made in the shape of a pig. By shrinking the proportions of the four legs, the unknown potter enabled his “pig” to lie comfortably on the ground. His tail rises upward and his ears extend forward, slightly hiding the eyes, while the teeth of the “pig” are clearly visible. Thus, an ordinary “living utensil” reflects the Sanlihe people’s love of pigs.
At the Sanlihe Cultural Relics Site, two rather unique constructions especially attracted attention from archaeologists and locals alike. One is a piece of rectangular land with length of 90 centimeters and width of 60 centimeters, the surface of which is covered with cobblestones. Discovered beside it was the buried body of a dog. Another site is a round pit with a diameter of 120 centimeters. Both the pit bottom and wall were carefully processed and lined with stones. The most probable explanation is that these two sites were constructed by ancient people as altars to offer sacrifices to their ancestors.