My son is 10 and is getting into the mountain biking. My $100 Walmart bike folded the handle bars at a pump track so its time to buy a real one to keep up with him.

Thinking trails and occasionally the easy downhill trails at the local ski mountains.

I was looking at hardtails and the nice people at the local bike shop recommended a Marlin 6 or 7 depending on price point.

I was also looking on the Trek website and was interested in the Roscoe.

I really dont know much and am open to other brands.

But the brain trust runs deep here at ARFCOM, so seeking advice, Thanks.

I am happy with my Roscoe 7 or 8. Wife has a Marin that is very nice aswell

I had an impossible time finding a decent youth bike locally so I bought a Vitus for my grandson from Chainreaction:
https://www.chainreactioncycles.com/us/en/vitus-nucleus-24-youth-hardtail-bike/rp-prod195891

Downhill trails at the local ski hill?  Full suspension without a doubt.  A hard tail is the wrong tool for that.

Marin and Trek both make good bikes.  My wife has a Marin and they seem to have good components for the price

I have a salsa journeyman which is more of a gravel bike (2.1'' tires) and it works fine for trails and light singletrack stuff

Best thing to do is see what the local dealers carry and compare components in the price range you are looking at.

Absolutely, budget 2.5k minimum.

I’d recommend Trek, Giant or specialized just to keep it simple

One good option if your downhill will include modest drops/jumps

https://www.giant-bicycles.com/us/trance-x-29-1-2022

I’d agree that if down hill/ski hill trails are in the forecast than a full suspension bike is worth considering. But, at 10 years old, that little dudes going to outgrow that bike fairly quickly.
You need a brutally honest assessment of what the bike will be used for, if he seriously likes it, and you can see him doing it at least semi-seriously, then it’s worth it to spend the money on the full suspension, if he just wants something to ride at a local park/pump track/xc trails, a Trek Marlin, Specialized Rockhopper, or similar offerings will be an excellent choice.

The 2022 Marlins look nice, I think at the Marlin 7 level you get a 1X drivetrain and hydraulic brakes at the ~$850 level

Love my trance. Great all around bike. Can handle down hill but also at home on the single track and climbing.  Great bike.

I went down this rabbit hole a couple years ago and ended up with a Specialized Rockhopper.

No ski slopes in Texas though.

One big thing to consider is buying used. MBX folks are juat like every other enthusiast group. They upgrade a lot to keep themselves interested. Find what you want and then look locally for a used one. Might save yourself a ton of cash to put towards accessories. A little under seat pack with a tube, patches, etc is a good idea.

I missed the 10 y/o part so yeah, something decent, safe BMXy plus maybe some classes and all the safety gear. Too much growing to come to go extreme