Fosters Hole or La Tinaja,[1]:168, n.2 was a waterhole on the original route of Cooke’s Wagon Road in what is now Sierra County, New Mexico. It is located in narrow crevasse at the foot of a cliff in Jug Canyon that is difficult to spot, except from a few vantage points.[2]
Lt. Colonel Philip St. George Cooke described Fosters Hole in his 1849 official journal of the expedition of his Mormon Battalion, from Santa Fe to San Diego:

“November 9.—Leroux came back last evening; he went down about fifty miles, struck off where the river turns east at San Diego, and in fifteen miles found some water holes; then he saw from a high hill a creek running out of the mountain at an estimated distance of thirty miles; the next water, over a rather level plain.”[3]:14

“November 13.— After following the river this morning a mile or more, we found a pole and note from Mr. Leroux, but met at the same time two of the guides, who directed us to leave the river short to the right, stating it was fifteen miles to water. I followed a smooth inclined plane (between two bluffs,) three miles, and then had a steep ascent; then following ridges and making ascents occasionally, we reached another inclined bed of a rainy-weather stream. From this we wound up a long valley to a ridge which bound it, following that over a very rocky prairie. Charboneaux had gone to the head of the inclined plane, and found, he thought, an outlet. The water is at its head; but he did not return in time to direct all the wagons, and it is doubtful with me if it would have been better. The wagons arrived at this ground about an hour by sun, having come fifteen or sixteen miles, and all up-hill; the prairie being usually gravelly, and not rough. The water is about 100 feet lower than the camp, in a rocky chasm, difficult of descent for animals. The chief supply is a natural rock-bound well, thirty feet in diameter, and twenty four feet deep. It contains about 55,000 gallons. Many feet below it are two smaller holes, which the animals can get at two or three at a time. There is no fuel, save a few bushes and Spanish bayonets. The country is well covered to-day with gamma grass, and, also, I saw buffalo grass. We came over a high point, and had a fine view of the Organos and “El Paso” mountains, and the mound called “San Diego,” where the river turns to the east. For a road coming up the river, there is a very fine valley, gradually ascending to this point. The course to-day, allowing for a variation of