Great bouldering in a remote area, Yankee Jim is a cluster of sparse, quality gneiss boulders with interesting features and bands.
Named after an old toll-road operator, Yankee Jim has a lot history, some of which is still noticeable so please exercise discretion and leave each area untouched and better then you found it.
While I've heard a few different names for some of the areas. The easiest division lies between two places called the Campground Boulders and The Loco-Motives.
If you're traveling to Yellowstone this makes a great stop before entering the park. The bouldering doesn't look like much, but its surprisingly fun and can be easily accessible.
As with most, the climbing is best in the spring and fall, with year-round bouldering available with a little chasing of shadows and sun. In the colder days you can feel the friction, where as in the summer the hard problems tend to feel harder.
A pay campground is available for a few dollars a night (Yankee Jim Campground) as is free camping in the national forest. If camping in the NF, please camp a good distance in from the road and pack out what you pack in. Be aware of private property and please keep off.
Only about an hour from Bozeman, Yankee Jim is found by taking I-90 east until reaching Livingston. Once here, look for exit 333 and drive south for 35 miles on highway 89 until you hit Tom Miner Road or the Yankee Jim Campground. If coming from Gardiner, MT take US Rt 89 north 12.9 miles till you hit the campground on the right.