1826 General Ashley sells his trapping interests in Wyoming.

1827  First wheeled vehicle, a four-pounder cannon, crosses South Pass.

1828  The first of Wyoming posts, known as “Portuguese Houses,” is established on Middle Fork of Powder River, 11 miles east of Kaycee.

1829  Smith, Jackson, and Sublette bring supplies to the rendezvous near the mouth of Popo Agie in mule-drawn wagons (first wagons ever brought to Wyoming).

1830  Kit Carson, noted scout, arrives.

1832 Captain B. L. E. Bonneville, with 110 men, 20 wagon loads of provisions, goods and ammunition, headed for Pierre's Hole, takes first wagons through South Pass and establishes temporary fortification on tributary of Green River. Built Fort Bonneville. He records presence of oil in Popo Agie region of Wyoming.

1834  Fort Laramie is established by William Sublette and Robert Campbell; was first permanent trading post in Wyoming (military post from 1849-1890).

 1835  Samuel Parker and Marcus Whitman are first missionaries to go across Wyoming. Rev. Parker held first protestant service in Wyoming near present Bondurant.

1836  Mrs. H. H. Spalding and Mrs. Marcus Whitman are first white women to pass over Oregon Trail.  They were accompanying their missionary husbands across Wyoming.

1838  Jim Baker joins American Fur Company; becomes noted scout and guide.

1840  Father Pierre J. DeSmet celebrates first Catholic mass in Wyoming on Green River, near the present-day town of Daniel.

1842  Fort Bridger, second permanent settlement, established by Jim Bridger and Louis Vasquez. (Military post from 1858-1890) Capt. John C. Fremont leads expedition to select sites for a line of military posts to lead to territorial acquisitions in the Far West. Names Fremont Peak. Elijah White leads large party of missionaries and settlers across Wyoming to Oregon. Gold discovered near South Pass.

1843 Fremont's 2nd expedition crosses Laramie Plains.

1845 Federal troops under Colonel Stephen W. Kearny march from Ft. Leavenworth to Ft. Laramie.

1846 President Polk approves act establishing military posts along Oregon Trail.