The California International Marathon (CIM) is one of the most established marathons in the country — a point-to-point race from the Sierra foothills above Folsom to the steps of the California State Capitol in Sacramento, run every year on the first Sunday in December. This guide pulls together the essentials: what the course is like, what the weather tends to do, how to get to the start, and how registration works — with links out to RaceRove's more detailed guides on each topic.

The course in brief

CIM runs in one direction only, starting in quiet, semi-rural terrain near Folsom Dam and finishing on Capitol Mall in downtown Sacramento. The route rolls through Orangevale, Citrus Heights, Fair Oaks, and Carmichael for a surprisingly large share of the race, with real climbs mixed into the net elevation loss, before flattening out almost entirely in the closing miles as the course crosses into the city. It's a course built for pacing discipline rather than a free downhill ride — see RaceRove's full course and elevation guides for the section-by-section detail.

Weather and what to expect in December

Early December in the Sacramento Valley tends to bring cool, calm mornings, occasional tule fog that usually thins out as the race goes on, and a real chance of rain given that Northern California's wet season is underway by then. None of those conditions are guaranteed in any given year, but runners should plan for variability rather than assuming a single typical CIM race-day forecast.

Getting to the start

This is a race with mandatory bus transportation for the final leg to the start — there's no driving up or being dropped off at Folsom Dam itself. Buses run early from a handful of designated pickup points in both Sacramento and Folsom, which is worth building into both your hotel choice and your race-morning schedule well ahead of time.

Registration and planning ahead

CIM has a well-earned reputation for selling out its entries early, driven in large part by its status as one of the country's most reliable Boston-qualifying and Olympic Trials-qualifying races. Runners planning to target CIM for a specific season should treat registering as an early step in their training plan, not something to sort out once training is already underway.

Race weekend basics

Packet pickup and the pre-race expo have shifted in recent years to a larger dedicated expo venue outside downtown, with free shuttles connecting it to the downtown hotel and finish-line area — worth checking the current year's expo location and shuttle schedule rather than assuming it's a short walk from the Capitol Mall finish. Race weekends often include an organized shakeout run the day before, open to any registered runner — a good way to meet other travelers and shake out race-day nerves if you're new to town. Starting corrals are self-seeded by your own goal pace on race morning rather than pre-assigned, so runners chasing a specific goal tend to start near others running a similar pace.

Why runners keep coming back

Between the net-downhill, point-to-point course, generally favorable December weather, and a deep, well-organized field, CIM has built a decades-long reputation as one of the best marathons in the country for runners chasing a specific time — while still remaining a legitimately scenic, well-supported race for anyone running it for the experience rather than the clock. If you're planning a broader trip around it, RaceRove's list of California races is a good place to see what else is nearby.

The essentials at a glance

• Course: point-to-point, net downhill, Folsom Dam to the California State Capitol, with rolling terrain that runs deeper into the race than the net-downhill label suggests.
• Weather: cool, calm December mornings on average, with real year-to-year variability including occasional tule fog and rain.
• Getting there: mandatory bus for the final leg to the start — no driving up or being dropped off at Folsom Dam itself.
• Registration: tiered entries that have sold out earlier each year in recent history, plus backup options like charity entries and a relay format.

Who this race is for

CIM works well for goal-oriented marathoners chasing a Boston or Olympic Trials qualifying time, thanks to the combination of terrain, weather, and a deep, competitive field. It also works for runners who simply want a well-organized, historic point-to-point course with a genuinely memorable finish at a state capitol — the two audiences overlap more than you'd expect, and the race doesn't ask you to choose between a serious attempt and an enjoyable day. Even runners with no specific time goal tend to come away impressed by how smoothly a race of this size is run, from the early-morning buses to the finish-area logistics — the kind of operational polish that only comes from decades of putting the same race on.