Still speculating here. If everything falls into place this summer I'll have ten weeks free.

San Antonio, friends in New Mexico, Las Vegas, Death Valley, Yosemite, big trees in California to Eureka CA on the North California coast works out to ~2,100 miles.

Assuming I accomplished that in six weeks or less, and still felt like it, I could go 80 miles north up the Pacific Coast and then hang a right towards the south entrance to Yellowstone via Grant's Pass, then north through Yellowstone to a good friend's house in Great Falls MT would add about 1,300 miles, ballparking 3,500 miles in ten weeks for the whole trip. Fifty miles a day.

That would be absolutely epic if I could pull it all off.

I know Yellowstone, and probably Yosemite, are packed in summer, can one cross these parks without prior reservations? Usual MO for me would be to sleep on the ground outside.

I live in Wyoming and have biked the park for 30 years.
From before the roads are opened to cars until closing date in the fall.

Yellowstone is doable - but there is considerable traffic and shoulders vary from moderate to none.
It really is best to cycle in the early, early morning - almost no traffic and lovely. Also into the evening.
You can bike late because all the campgrounds but one (PebbleCreek) have reserved hiker/biker campsites.

Yellowstone's road system look like a "Figure 8" with 5 entrances.
The lower, larger loop generally has good shoulders with the exception of Canyon-Lake.
The smaller, upper box has narrower roads with few shoulders.
(The Mammoth-Norris segment is under reconstruction and will be much improved.)

The West and East Entrance roads are excellent with shoulders.
The Northeast Entrance road is narrow but with much less traffic.
The North Entrance is steep, narrow, with hairpin curves.
The South Entrance is fairly steep with no shoulders - challenging northbound.
I always try to ride it late when there is shade and lighter traffic - camping at Lewis Lake.

I suggest a south to north route -
South Entrance, West Thumb, Lake, Canyon, Norris, Mammoth, North Entrance
From West Thumb to Lake you follow the lake shore - Gull Point Road is a nice back road loop.
Lake to Canyon is a stunning ride along the Yellowstone River thru the American Serengeti.
Canyon has great camping, services, showers, laundry - and fabulous hiking along the canyon rim.
Norris Geyser Basin is far less touristy than Old Faithful - esp. in the early morning or evening.

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US 89 is a sweet route up to Great Falls.
Use back roads on the east side of the Yellowstone River from the park to Livingston.

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If mid-summer, consider riding via Stanley, Idaho thru the Sawtooth Mountains.
Stunning scenery and cool temps rather than baking in the Snake River Plain.

Unless things have changed since I was there many years ago, the campgrounds will make space for cyclists. In fact, I was told I could not make reservations because I was on a bike.

Wow- I am also in San Antonio and I am also riding this route (more or less) this summer, only in reverse, as the homeward leg of my tour. My friends are in Arizona and my west coast destination is my brother in San Francisco. Thank you, Jamawani, for your response! I came close to Yellowstone on a previous tour and have said to myself ever since,"next time". Your information is just what I need to proceed with an even greater degree of excitement, from the point of view of an experienced bicyclist. I am eager to ride Death Valley as well, as my brother rode it in the 90s and made it sound incredible. I recall he had a sign on the rear of the bike, H20?, inviting cars to stop and offer water, which I found clever. Sharpshin, have a great trip- maybe we'll cross paths in the desert!

Don't spend too much time cycling North on the Cali coast. Or any of the Pacific coast. You get ridiculous prevailing headwinds, no view, and far fewer shoulders.

The Yellowstone part of your question has been answered I see. Just heads-up about the coast road. Sounds fun otherwise. Plan on one rest day a week makes some sense.

Cheers.

Was going to mention this. OP said something about 80 miles up coast. OP, is that 80 miles a day? If so, unless you are in super phenomenal iron man level shape, You aren't going 80 miles a day on the coast.going north.

For The Yellowstone part .. Bear box and never eat in your tent.. .... if you have before... get a new tent and never do that again

Bears sense of smell as far as food goes is very good. .. they may tear up your tent looking for the food you may have spilled last year.


+1) summer high, weather map fans , rotates clockwise .. so off the North pacific that cell spins winds down from the north....

If you go in the winter low pressure cells rotate counterclockwise so storms blow from the south..

Go in Spring after roads plowed and it's open to bikes only.

https://www.nps.gov/yell/planyourvis...-bicycling.htm

Overnighter from W Yell to Mammoth & back:

Problem with spring is that it can literally be freezing. Some people don't realize that Old Faithful sits at 6,000'. When I was there in late June I woke up at Grant Village to find frost on the ground.

Actually, Old Faithful is almost 7500 ft. - one of the "lower" points in the park.
Much of the park is 7500-8500 ft. - so summer comes late and departs early.
One should expect snow and freezing temps in June.
Many park areas - campgrounds/concessions - do not open until late June.
Few services are available before Memorial Day - with the exception of Mammoth.

I have ridden early season - after roads are plowed but cars are still excluded.
One trip in the 1990s I was the only person - not one other all day.
Rode along Yellowstone Lake with giant icebergs on the shore.
(They no longer allow early riding along Yellowstone - grizzly habitat.)
But much of the riding was also just between walls of snow.

I cycle at such a sedate pace that cycling IS a rest day. three rest days over 33 days 2,000 miles TX to NY, only really needed the first one on day five after I had put in ~300 miles in four days. Set a more relaxed pace after that.Typically I start in late morning after lingering over breakfast and then ride until nearly full dark, cold camp near the roadway. Average pace of actual riding: about 8mph.

I wouldn't follow a late morning start strategy riding in Yellowstone. Hit the road early while more of the car crowd is still in camp or wherever.

From what I remember, the Yellowstone tour busses hit the road at 8:30. Most other tourists started loading their cars about 9:30, and the traffic jams started shortly after 10:00. Four hours of clear roads in the morning if you leave early enough.

OTOH, almost everybody is off the road by 5:30. It's almost impossible to get into a restaurant between 5:30 and 8:30.

I entered the park at W. Yellowstone pretty early. Not much traffic during my short jaunt to Madison Campground. But one car did pull along side me. The woman in the front seat said "Hi, Dave." It was a woman who had been on my cross country tour the previous year.

The next morning I got an early start to Grant Village. Most of the car/RV crowd at Madison was still asleep. Maid it Old Faithful with little traffic, but made the mistake of hanging there to wait for the geyser to go off. The rest of the ride to Grant Village was not fun. I nearly got doored by someone in an "animal jam." Luckily, I was going up hill slowly. Turned out there was no animal to be seen.

Thank you for the input all.

Looks like I'll have to adjust my MO in Yellowstone and maybe other places. I sleep out, cold camp, bottle of Diet Coke for morning caffeine at hand. Head out, stopi at the first place I come across to eat, pay for breakfast, hang out for a bit, then ride the rest of the day. Only food I pack is a mixture of granola and dry oatmeal, after stopping for the night I'll add either water or milk (if stores lay along the route) and eat it cold and uncooked like cereal right before I go to sleep in the tent.

Please do not eat in your tent.
Not while you are in Yellowstone.
Not for weeks before.

How about just NEVER eat in your tent. Raccoons are everywhere. So are rodents, ants, skunks, etc. They will ruin your stuff. Deer will eat your sweaty helmet pads if you leave that lying about.