Friday, 13th. Traveled about 10 miles in a southerly direction. It was the intention of the company to stop and hunt in Cash valley, which is on Bear river 3 or 4 days’ travel from its mouth.
He means Cache Valley, in northern Utah. Captain Fitzpatrick would have mentioned it as a good place to rest and hunt.
Cache Valley was well known to the fur trappers of the early 19th century. It was sometimes the site of rendezvous and was considered a good place to “cache” your furs until it was time to take the lot back to Missouri for sale. It is a beautiful well-watered fertile valley between the Rockies and the ranges of the Great Basin.
Today the Cache Valley is a well-populated area, with a major city (Logan) and lots of farms.
But the Company is not there yet. They still have several days of travel down a river hemmed in by hills before they get to the valley. And on the 13th, Jimmy John said:
The river here runs thru a deep channel of black rock which has the appearance of being melted by volcanic eruptions and not by earthquakes.
They were probably trying to get through Black Canyon. It is now a popular place for kayaking.