Following is a state-by-state roundup of the West (numbers in parentheses are Electoral College votes): Alaska (3)

The oil-based, supply-side pioneer society of Alaska is ready-made for Ronald Reagan Republicanism and a repetition of the GOP's 1980 sweep, when Reagan ran 2 to 1 ahead of President Jimmy Carter. He could do even better this time and still trail Sen. Ted Stevens (R), who, as of Sept. 30, had raised $1.1 million, compared with $78,900 for his Democratic opponent, former state attorney general John E. Havelock. Arizona (7)

Arizona last voted Democratic for president in 1948, and Democratic presidential nominee Walter F. Mondale is not the man to break that losing streak. All the focus is on the House rematch between freshman Rep. James F. McNulty (D) and former state senator Jim Kolbe (R). McNulty won by 2,407 votes last time, but registration shifts and Reagan coattails make it tough for him to repeat his victory, despite his skillful exploitation of his incumbency. California (47)

Despite a $3 million investment and repeated campaign forays, Mondale, running mate Geraldine A. Ferraro and a host of Democratic surrogates have not been able to break Reagan's grip on his home state. The latest Post-ABC poll puts Reagan up 50 to 44 percent and the Field Poll has him leading by 16 percent. Mondale is coming back Monday, but even within his campaign organization, there is now little hope of an upset.

In addition to Reagan's personal appeal, which has carried him to victory every time his name has been on the ballot here, Republicans won the registration war, 740,000 to 656,000 in the state and in the districts of two endangered House Democrats.

Rep. George E. Brown (D) is facing San Bernardino insurance man John Paul Stark (R) for the third time in a district which is becoming more Republican in its makeup. Rep. Jerry M. Patterson (D), perpetually in tough races, faces former representative Robert K. Dornan (R), a controversial conservative who moved down from Los Angeles in an effort to purge the only Democrat holding an Orange County House seat. Reagan's coattails will be awesome in this district. In a banner year, the GOP sees chances of an upset of freshman Rep. Matthew G. Martinez (D) by Richard Gomez (R). Colorado (8)

It might have been different -- at least in the margins -- if Colorado Sen. Gary Hart had been the Democratic presidential nominee, but the Denver Post poll published after the last debate put Reagan ahead of Mondale, 61 to 31 percent. Sen. William L. Armstrong (R) has almost as big a lead for a second term over Lt. Gov. Nancy Dick (D).

The House seat being vacated by Rep. Ray Kogovsek (D) seems likely to switch to the GOP. Both parties' polls have former state representative Michael L. Strang (R) ahead of environmental activist W Mitchell, former mayor of Crested Butte. Hawaii (4)

After missing by only 7,300 votes in 1976 and 5,700 votes in 1980, Republicans have a good chance at breaking the Democrats' near-monopoly on Hawaii's electoral balloting. Thursday's Honolulu Advertiser poll had Reagan ahead, 49 to 39 percent, despite union and Democratic establishment support for Mondale. A hot mayoral race in Honolulu could pull a big enough turnout to thwart Reagan. Idaho (4)

Reagan may break 70 percent this time here, a state that vies with Utah for being his best. Sen. James A. McClure (R) should do as well in his third term bid against Lewiston realtor Pete Busch (D).

Rep. George Hansen (R), convicted of four felony counts of violating the Ethics in Government Act and reprimanded by the House, is in a furious fight to save his seat in a rematch with Ricks College Professor Richard Stallings (D), who came close in 1982. Stallings has led the preelection polls, but Hansen has a way of escaping predicted ruin; this time, he has cited Ferraro's financial disclosure problems in an effort to persuade his constituents that he has been singled out for persecution. And Hansen has been winning some of the high school straw polls. Montana (4)

As if Mondale did not face enough troubles here, the AFL-CIO, which is his main support in the state, has been hit by an investigation into the alleged use of state employes for political work.

Despite Reagan's big lead, Sen. Max Baucus (D) is favored to breeze to a second term over former state representative Chuck Cozzens (R), who drew criticism for radio ads calling Baucus "a wimp."

Gov. Ted Schwinden (D) is so popular for his fiscal conservatism and economic development plans that Republicans had a hard time recruiting state Sen. Pat Goodover (R) to oppose a second-term bid that could produce a record gubernatorial majority. Nevada (4)

The big brass of the Reagan-Republican campaign, Sen. Paul Laxalt (R-Nev.) and his protege, Republican National Chairman Frank J. Fahrenkopf Jr., will not be embarrassed by the home folks.

Reagan can almost name his margin, but the two-member House delegation is likely to stay split between the parties. New Mexico (5)

Time was when this was one Rocky Mountain state the Democrats might win, but not lately. The party still has a 3-to-1 registration edge, but Mondale is barely ahead among Hispanics in state polls and Reagan is leading by at least 15 points overall. Sen. Pete V. Domenici (R) is far out in front of liberal state Rep. Judith A. Pratt (D), and could top 70 percent of the vote as he gains a third term. Oregon (7)

Mondale and Ferraro have lavished attention on this small state, where the unemployment is above average and Reagan's social issues do not play well. But the GOP ticket is still on top, with a 52-to-42 percent lead in Friday's Portland Oregonian poll.

Sen. Mark O. Hatfield (R), embarrassed but not weakened by a summer report about his family finances, is headed for a fourth term over underfinanced state Sen. Margie Hendriksen (D).

Rep. Les AuCoin (D) has had a struggle with retired businessman Bill Moshofsky (R), who came close in his first try in 1982, but AuCoin is judged hard to beat in the Portland area.

Similarly, Rep. Denny Smith (R) is at least a slight favorite in his rematch with state Sen. Ruth McFarland (D), who gave him a scare two years ago. Utah (5)

The only question in the presidential race is whether Reagan can top the 73 percent mark he hit in Utah -- his best state -- in 1980.

With Gov. Scott M. Matheson (D) retiring, Republicans are favored to end a 20-year run of Democratic governors.

State House Speaker Norman H. Bangerter (R), promising no tax hikes for two years, is running 12 points ahead of former representative Wayne Owens (D). The Deseret News poll Saturday had the race 53 to 41 percent for Bangerter. It is a very tight race in Salt Lake City's House district, where Rep. Dan Marriott (R) stepped down to make what turned out to be an unsuccessful run for the gubernatorial nomination.

Former state senator Frances Farley (D), who came close in 1982, took an early lead over Lt. Gov. David S. Monson (R), who has had adverse publicity about financial disclosure questions, but the same poll Saturday had the race 48 to 44 percent in favor of Monson. Washington (10)

Like the other Pacific Coast states, Washington has been better territory for Mondale and Ferraro, who have campaigned here frequently, than most of the country. But public and private polls show Reagan leading by between 6 and 12 points.

The state's focus has been on Republican Gov. John Spellman's uphill battle for a second term against Pierce County (Tacoma) Executive Booth Gardner (D). Their race has been described as a contest between "the wimp and the waffle."

Gardner, a Weyerhaeuser heir, is a shy, unexciting campaigner, with a high-pitched voice, but Spellman has gained a reputation for indecisiveness in the last four years.

Spellman's TV ads, attacking Gardner as a "puppet for union bosses," caused the Teamsters union to withdraw its endorsement of the governor last week, but apparently -- along with campaign help from popular Republican Sens. Daniel J. Evans and Slade Gorton -- they have narrowed the deficit from 20 to eight points in late polls.

In the district left open by the retirement of Rep. Joel Pritchard (R), former Seattle councilman and TV commentator John Miller (R), a moderate like Pritchard, is a very slight favorite over Brock Evans (D), lawyer and Sierra Club-Audubon Society official, who inherits good name recognition from the unrelated Sen. Evans and former Seattle congressman and U.S. Transportation Secretary Brock Adams. Wyoming (3)

The only contest here is to see which of three Republicans leads the ticket: Reagan, Sen. Alan K. Simpson, headed for a second term over University of Wyoming professor Victor A. Ryan (D), or Rep. Dick Cheney (R). It's a friendly rivalry.