Writing-on-Stone Provincial Park - Alberta, Canada
Posted by: 
T0SHEA
N 49° 04.961 W 111° 37.296
12U E 454610 N 5436833
Writing-on-Stone is an area of sandstone formations and hoodoos on the north side of the Milk River Valley in southern Alberta. Natives gathered here for centuries and left pictographs and petroglyphs as witness to their presence.
Waymark Code: WMGADC
Location: Alberta, Canada
Date Posted: 02/05/2013
Views: 7
The outcrops of sandstone found here are excellent examples of the type of formations created principally by great amounts of water flowing during the melting of the glaciers between 10,000 and 20,000 years ago. There are many formations of this type in Alberta, this being one of the largest and most spectacular.
The largest concentration of First Nation petroglyphs and pictographs on the great plains of North America is to be found here.
From Parks Alberta: http://www.albertaparks.ca/writing-on-stone/information-facilities/natural-cultural-heritage/natural-heritage.aspx
"This park preserves spectacular badlands, riparian habitats and grasslands along the Milk River. The unusual landforms of Writing-on-Stone / Áísínai'pi resulted from the dynamic interaction of geology, climate and time. The sedimentary rocks exposed in the Milk River valley were formed 85 million years ago at the edge of a great inland sea. Huge volumes of meltwater began eroding the soft sandstone after the last ice age. This is how the coulees and hoodoos you see today were formed. The unique habitat created is suitable to many diverse species not typically found in surrounding areas.
During the Cretaceous Period, Writing-on-Stone / Áísínai'pi lay at the western edge of the Pakowki Sea. Mud, sand and clay were deposited as this inland sea slowly retreated. Over millions of years, these sediments were buried, compressed and hardened into the sedimentary rocks of the Milk River Formation.
During the Wisconsin glaciation (approximately 70,000 to 10,000 years ago), Writing-on-Stone / Áísínai'pi lay deep beneath the Laurentide ice sheet. The ice sheet began to melt some 20,000 years ago, retreating to the northeast. Large lakes formed along the southern margins of the ice sheet. These are known as proglacial or ice margin lakes.
The ice acted as a dam, forcing a huge volume of water to drain south from the proglacial lake. This created deep meltwater channels - the prairie coulees we see today. The meltwater also eroded the ancestral Milk River valley.
Today, the Milk River is the only river in Alberta that flows south into the Mississippi basin."
