This is rough, but:
April 1846 - UK and US in negotiations for the Oregon Treaty, Mexican-American War starts. UK takes a tougher line in negotiations - says unless Oregon Country is given over to the UK, then it will take the view that USN activity in the Caribbean is a threat to British Colonies, and the Royal Navy will keep the sea free for all commerce, including Mexican.
September 1846 - Polk decides not to risk conflict with the UK at the same time as war with Mexico, but still wants a corridor to the Pacific. Signs a deal that gives all of the Oregon Country north of 44 degrees to the UK (OTL border is at 49 North, and California is south of 42. This puts the border just south of OTL Eugene).
1848 - Treaty of Guadalupe Hidalgo between US and Mexico. With its northern expansion limited the US is more aggressive and acquires more Alta California, Santa Fe de Nuevo México, Baja California, Sinaloa and Sonora, while the boundary with Texas was set at the Rio Grande (in OTL, Baja, Sinaloa and most of Sonora were left to Mexico). As a result the US has a much greater focus south.
1849 - Gold Rush in California worries British in their underpopulated Oregon Colony. Troops and ships are rushed to the colony to ensure it stays British. Vancouver on the Columbia becomes a large port.
1861 - US Civil War breaks out, complicated by the fact that some of the new territories acquired from Mexico have been admitted as slave states. The UK further reinforces Oregon, just as they did Canada at the same time. Gold rush in the Cariboo country brings population into upper Oregon.
1862 - Naval warfare breaks out between the USA and CSA in the Pacific with raids on the Californian and Sinaloan coasts. The UK, alarmed by this expansion of the war, annex Hawaii, simply arguing that Paulet's actions in 1843 were legitimate.
1863 - The legislative assembly of the Oregon Crown Colony is convened for the first time. James Douglas is Governor.
1867 - Confederation of Canada - Oregon is not included (just as in OTL British Columbia were not included initially).
Late 1860's - British trade between Hawaii and Oregon grows. Settlers overwhelmingly come around the Horn by ship and not overland. The colony thinks of itself as a Pacific colony rather than a North American one. With an economy focused on resources and gold rushes it resembles Australia more than Canada.
1871 - Rupert's Land is divided between Canada and Oregon at the 110th meridian. Oregon now extends to the Arctic ocean.
1873 - Oregon railway begins construction - up the Columbia valley, through Rogers pass and down the Bow Valley - it will take nearly 20 years to complete
1880 - Russia sells Alaska to the United States. Britain is too much of a rival to sell to them, and by now the US is more interested in the Northern Pacific.
1882 - Royal Navy base constructed on Puget Sound. The city of Nelson springs about around it (OTL Tacoma)
1892 - The Oregon Railway to Calgary is completed. Plans are made for an all-British transcontinental railway to Canada. Construction begins the next year in northern Ontario.
1898 - Gold is discovered in Oregon's Yukon division. Another gold rush ensues. To better deal with influx of prospectors and to maintain security, Oregon begins the path towards becoming a self-government.
May 1, 1899 - Oregon becomes a self-governing Dominion within the British Empire. The population is about 650,000, primarily focused in the Willamette Valley, Puget Sound, southern Vancouver Island and the lower Fraser Valley. The new Dominion is divided into 9 provinces (each with their own weak legislature): Willamette, Columbia, Puget (OTL's Washington and Oregon west of the Cascades), Okanagan (the interior from 44 degrees north to the Thompson river, west of the Rockies), Vancouver Island, Fraser (OTL's SW BC and coast range), Edward (west of the Rockies, south of 52 North), Saskatchewan (west of the Rockies north of 52 degrees) and Yukon (everything from the Thompson to the Arctic).
1902 - Oregon drops Pounds Sterling as their currency and adopts the Oregon Dollar.
1906 - Hawaii adopts the Oregon dollar and trade links increase.
1914 - Oregon battalions march off to war with the rest of the Empire. The Rocky Mountain Rangers distinguish themselves at Gallipoli fighting beside the ANZACs and the Hawaiian Light Infantry.
1930 - Hawaii declares bankruptcy and asks to be put under direct Imperial rule.
1931 - Oregon signs the Statue of Westminster, but remains part of the Empire.
1938 - Oregon offers to assume Hawaii's debt, if they join Oregon. This plan is put forward by the young minister of foreign affairs, W.A.C Bennett. The Imperial authorities are delighted to have someone take Hawaii off their hands.
May 1, 1939 - On the 40th anniversary of Oregon becoming a Dominion, Hawaii joins as two provinces - Hawaii (the big Island and Maui), and Cook (Oahu and the rest). The British Pacific Fleet remains headquartered at New Portsmouth (OTL Pearl Harbour).
September 3, 1939 - Oregon declares war on Germany.
December 7, 1941 - Japanese carrier-borne aircraft destroy part of the British Pacific fleet at anchor in New Portsmouth. Japanese troops invade British territories in Asia including Hong Kong and Malaya at the same time.
1942 - Isolationist fleeing rises in the US, but the US oil embargo against Japan continues. Japanese troops seize oil producing areas of the Dutch East Indies.
June 1942 - The "Siege of Hawaii" begins. Japanese forces take Midway Island, and use it for ground based bombing of Hawaii. Subs of the IJN prowl around the islands sinking supply ships from continental Oregon and crucially, from the USA. Oregon embarks on a significant ship building program with big yards at Burrard, Nelson and Vancouver.
July 1942 - Battle of Nelson - carrier based Japanese planes raid Nelson hitting the ship building facilities and fuel storage tanks. The raid is not a complete success thanks to new radar installations on the coast. A dog fight ensues over Nelson and the Japanese planes are hit by Vancouver Island-based fighters on the return to the carriers. A destroyer squadron chases after the raiding carrier fleet, but only manages to catch part of their destroyer screen. The news is reported that the RON ships scared off the Japanese fleet. This is the last time the Japanese will threaten the coast of North America.
August and September 1942 - After the raid on Nelson, FDR is increasingly worried about the Japanese threat to the US. He considers a threat continental North America to be a threat to the United States. He orders USN ships to escort US merchant ships in the Pacific to the defend them against any aggressor. There are several incidents as US merchant ships are sunk by Japanese subs and bombers around Hawaii. USN ships are damaged.
October 29th, 1942 - Japanese troops invade the US-held Philippines. They were convinced that FDR was creating a pretext for war, and decided to strike first to gain the element of surprise.
November 8th, 1942 - The first USN convoy arrives at New Portsmouth, marking the end of the "Siege of Hawaii."
November 10th, 1942 - Hitler declares war on the United States. The delay of the US entering the war nearly a year later than in OTL greatly slows down the winning of the war, as the Japanese have time to expand their fleet, and the Germans are subjected to less bombing and less distractions like the liberation of North Africa.
1943-1947 - Oregon troops are an integral part of the liberation of the Pacific.
September 14th, 1946 - The USAAF drops the first nuclear weapon on Berlin. Germany surrenders two weeks later.
January 1, 1947 - The Soviet Union declares war on Japan. Seizes Manchuria, and launches raids on Hokkaido.
May 1947 - Three nuclear bombs dropped on Japanese cities. Japan surrenders on June 1st. Like Germany and Austria, Japan is occupied by the victorious powers. The USSR occupies Hokkaido and the Tohoku region, the US the rest of Honshu, Britain and Australia jointly occupy Kyushu and Oregon occupies Shikoku.
After the war Oregon starts to re-build its civilian economy. With a population of only 5 million, it had nearly 700,000 people in uniform by the end of the war. The Royal Oregon Navy is the third largest force in the Pacific.
1948 - The United Nations is formed with Oregon one of the initial members.
1952-1957 - Far Eastern War - communist forces in North Korea and North Japan launch coordinated invasions of the free souths of each country. The Soviet Navy effectively bottles up the sea of Japan. A cease-fire is signed in Japan once the allies have liberated all of Honshu. Korea was always something of a side-show and very few Oregon troops fought there. South Korea is conquered by the North as the UN response deteriorates into just strategic bombing.
1965-70 - Oregon provides a limited number of military advisers to South Vietnam, but is much more focused on the North Pacific.
1950's to 70's - Hawaii becomes a major tourist destination and Oregon liberalizes its trade laws making Hawaii the entrepot of the Pacific. With good rail links to both Canada and the US, more and more container ships call at Nelson, and Columbiaport - the new port just down river from Vancouver. There is significant Japanese immigration from Shikoku to mainland Oregon.
1986 - Oregon signs a free-trade agreement with Australia. Called the Pacific Trade Agreement (PTA) it opens up oceanic trade. New Zealand joins the next year. The United States joins in 1991, followed by Singapore in 1994, Japan follows in 2002.
1994 - The Soviet Union falls. The People's Democratic Republic of Hokkaido is abolished and rejoins the Japanese Federation.
1995 - The last Oregon airbase in Japan is closed and the planes and crews come home.
2013 - Oregon is developed nation of 19 million people which consistently tops the lists of countries with the highest standard of living in the world.