The Adams County Courthouse is located at 1100 Judicial Center Drive, Brighton CO 80601; phone: 303‑659‑1161.
This county was originally a part of Arapahoe County, which was settled in 1858 by gold- hunters. It was organized in 1902, with an area of 1,253 square miles. The surface consists of rolling plains, well adapted for grazing and general farming. The elevation of Adams County is from 4,000 to 5,000 feet above sea level. The mean annual rainfall is about 15 inches, and the mean annual temperature from 45° to 50°. Population in 1910 was 8,892.
The line of the Union Pacific follows closely the route of the exploring expedition of Major Long and party. On July 4, 1820, their camp was at a point near the present site of Brighton, and they proceeded up the river to a spot within the corporation limits of the Denver of today.
Fremont, on his second expedition, traversed this section. In his journal for July 7, 1843, he says: "We made this morning an early start, continuing to travel up the Platte; and in a few miles frequent bands of horses and mules, scattered for several miles about, indicated our approach to the Arapaho village, which we found encamped in a beautiful bottom, and consisting of about one hundred and sixty lodges ... Continuing in the afternoon our route along the mountains, which were dark, misty, and shrouded — threatening a storm; the snow peaks sometimes glittering through the clouds beyond the first ridge."
"We surprised a grizzly bear sauntering along the river, which, raising himself upon his hind legs, took a deliberate survey of us that did not appear very satisfactory to him, and he scrambled into the river and swam to the opposite side. We halted for the night a little above Cherry Creek."
Parties of Southerners bound for California in the mid-century [19th] occasionally passed that way. There was then a broad, beaten trail along the river, which had long been known to freighters and trappers; it was also the route of military expeditions going back and forth between Fort Union and Fort Laramie.