did near the Needles rock formation near the modern Utah-Wyoming border.

Had the Army advanced, the Mormons had constructed interesting defenses to confront it in Echo Canyon, East Canyon and even at Mormon Flats in Little Emigration Canyon.

In Echo Canyon, Eldredge said Mormons hoped to ambush the Army, if necessary, at a point where it narrows, about a mile east of the current rest stop and welcome center on I-80. He points to well-concealed but still visible circular rock nests atop the cliffs. On the other side of the canyon, Mormons dug rifle pits, now long-vanished. Had the Army advanced, Mormons could have poured in fire from well-concealed fortifications on both sides of the canyon near its narrows.

Across the canyon floor, Eldredge said, Mormons dug several trenches — about 12 feet wide and eight feet deep — which would slow any Army advance while Mormons fired from canyon walls. They also built dams to flood some narrow points. Similar fortifications were built in East Canyon, just upstream from where East Canyon Creek enters modern East Canyon Reservoir. These are most easily seen today above Mormon Flats in Little Emigration Canyon.

Mormon militia were scattered from Salt Lake City to Cache Cave near the top of Echo Canyon to fight if the Army advanced, with spies stationed from there to Camp Scott.

The Mormons manning such fortifications did not have an easy winter. A captured Army teamster later wrote that among Mormon troops, "Remnants of old bed quilts and blankets served as overcoats." Many had no shoes and no tents.

However miserable the winter was for the Army and the Mormon militia, it bought time for cooler heads to prevail and negotiate peace.

The era's press and opposition politicians began to berate the Buchanan administration for the war's cost and poor execution. One cartoon showed Young hiding behind polygamous wives — which it called his breastworks — scattering the Army into a frenzy with well-placed shots.

Buchanan started looking for a way out of the mess.

Col. Thomas Kane, who had been a longtime unofficial ambassador for Mormons in Washington, was authorized by Buchanan to come West to try to negotiate peace. Buchanan also later sent two other emissaries.

Buchanan eventually offered "amnesty" to Mormons. In exchange, the Army would be allowed to establish a permanent fort nearby: Camp Floyd in Cedar Valley.

Johnston wasn't happy. As he marched troops through Salt Lake City the next June, he told Maj. Fitz-John Porter that he "would give up his plantation for a chance to bombard the city for 15 minutes."

The "war" would forever change Utah. The influx of non-Mormons it brought would never again allow the territory to be a Mormons-only enclave.