Bozeman is a very nice airport and convenient. If you are interested it also has bus service to Yellowstone. West Yellowstone has United and Delta service, but many fewer flights - and more expensive. Some people fly to Jackson, but the flights are also more limited and more expensive (although Bozeman too is a regional and not the choice or lower cost of flying into a hub (i.e. LAS, DEN, SLC etc.).

There will be a places to park at the Trail Head.

We spent a few days in YNP in July and did drive to Lamar Valley to see wildlife. Waste of time. It’s a long drive from Mammoth Hot Springs (with partial loop closure), even longer from West Yellowstone, and the only animals we saw were bisons. You see them all around YNP, and at closer range than in Lamar Valley.

We flew into Bozeman, too. It was a great place to spend some time; we stayed at the C'mon Inn if you are looking to stay. It's a great hotel We staying in the park at the Mammoth Inn 3 nights and then stayed in the four corners of Yellowstone, West Yellowstone, Cooke City, Cody and Jackson. All were lovely places and we enjoyed them additionally to Yellowstone. We rented a car at the airport which was more convenient and didn't seem much more expensive. You will love Yellowstone and see the Grand Tetons too if you have time. We had such a great trip and would quickly do it again.

Lamar Valley is open all year round. You would have to go through the North entrances. Have fun

Not sure about RV parking overnight near park. I know you can camp inside park but not sure about RV’s. Lamar Valley is open all year round and yes it’s where you see the most animals. Summer is the time to go for wildlife so I hear. Pack snacks, water and look for animals. Just park at the pullouts, use your binoculars and you’ll most likely see something. Have a good trip.

We saw a ton of animals on our own. No tours required, in my opinion. But - we did our homework and researched where and when it would be most likely to see animals (be in the Lamar Valley at dawn for best odds of grizzly, wolf and bison sitings). Sorry - can’t comment on accommodations in Gardiner - we camped in West Yellowstone.

Bisons are everywhere, even in the middle of the road. Drive carefully around the turning. On late afternoon we saw many more wildlife(bears, elk, moose, deer). They are not only in Lamar Valley, but on the way there.

Here is the itinerary for our October visit copied from my travel blog. We flew in late on October 7 2018, with 2 nights in Jackson, staying at the Parkway Inn. Mon 8 October: Woke up to gorgeous weather, but storms are forecast this week, so tried to make the most of it. Hit the Visitors Centre, grabbed some maps and Bear Spray and headed out towards the Grand Teton Mountains. Stopped at an abandoned Mormon settlement, and saw some Prong Horn Antelope just beside the road. It’s the tail end of Autumn here, but there are still some beautiful fall colours on display. Crossed the Snake River, and came across a family of Moose grazing in a swamp (Note: this was just off the Moose Wilson Rd). We hiked up above Phelps Lake to see spectacular views out towards the Gros Ventre range, and some Mule Deer crossed the trail on our way down. Walked around Jackson township, and had a drink at the Million Dollar Cowboy Bar before dinner. Quite a day! Tues 9 October: Winter weather arrived today, with low cloud, rain and a little snow, so we came inside to the wonderful National Museum of Wildlife Art. Next we headed up into Grand Teton National Park, seeing a several Bison along the way. We‘re in a cosy cabin right on the lake at Signal Mountain for the next three days. Wednesday 10 October: A bit of light snow overnight, but a lovely clear morning. Our cabin is right on Jackson Lake, and we walked along the shore before breakfast - just a bit chilly! Drove up to the top of Signal Mountain, then down to Jenny Lake. Did a long hike around the southern end to Hidden Falls and Inspiration Point, and a quick walk around the Menor’s Ferry historic district. Saw some Mule Deer on our way back, just as it started to snow again. Thursday 11 October: Woke to a winter wonderland. Light snow overnight, but thankfully the roads were still clear. Drove to Jackson Lake Dam, then back to Ox Bow bend to watch the bird life. We walked through pine forests to Swan Lake, with light snow falling - beautiful, but a little scary as we were the only ones out there, and on our return we saw (maybe) bear tracks. A sleek coyote ran across the road on the drive back, and its friend was a little further on, but they were too quick to take a photo. Did a more substantial hike out to Bradley Lake and Beaver Creek in the afternoon, with fabulous views of the mountains. There were more Pronghorns on the way to Dornan’s Bar, and we saw our first Elk the distance. As we headed home, another group of Elk crossed the road. Off to Yellowstone tomorrow. Friday 12 October: Another sunny day, so we decided to hike before heading off to Yellowstone. We drove to String Lake, and walked along the eastern side. There was no wind, and the mountains were reflected in the water - gorgeous picture postcard stuff! We saw another moose wading near the edge, but she heard us and moved quickly into the forest. We went about halfway around Leigh Lake before returning. Great morning! Later we drove back past the Snake River overlook and Ox Bow bend, then along the John D. Rockefeller Jr Parkway from Grand Teton into Yellowstone National Park. We stopped at Lewis Falls and the West Thumb Geyser Basin, and another coyote crossed our path just near the continental divide marker. Saw our first Bison just before checking in to our (very rustic!) cabin at the Old Faithful Snow Lodge. Saturday 13 October: Snowing quite heavily this morning, and a lot of the roads through Yellowstone were blocked. We watched Old Faithful Geyser erupt, explored the village, and played a game of Scrabble. The sun came out in the afternoon, and we drove to Middle Geyser Basin, Firehole Lake Drive, Gibbon Falls, and the Artist’s Paint Pots area. Saw some more Bison on the way back. Sunday 14 October: Gorgeous day, but a lot of the roads still blocked by snow, so explored the Norris Geyser Basin area. So slippery on the trail, and on the way out cars were sliding everywhere! However, they did open the road to the Grand Canyon of the Yellowstone. Just a little bit spectacular! Headed down through the Hayden Valley, and saw a herd of Bison running just beside the road, including a young calf and a huge bull, but unfortunately nowhere to pull up for photos. Stopped at the Mud Volcano area and Yellowstone Lake, but Craig Pass was still closed, so had to drive the long way back through Canyon, Norris and Madison. Monday 15 October: Our last day in South Yellowstone. Climbed to Observation Point above the village to watch Old Faithful erupt, then walked the Main Geyser Basin. Packed up and drove through the beautiful Yellowstone Lakes area, stopping for lunch in a snowy picnic spot beside the river. We saw lots of bison in the Hayden Valley, and this time managed to take some photos. Dunraven Pass was supposed to be closed for winter a week ago, but luckily it reopened today, and we could drive over the mountains to Tower Fall, a waterfall which plummets between hoodoo rock pinnacles. Walked down the trail below the falls, and saw (yikes!) bear tracks in the snow. Headed through the historic Yellowstone North Gate arch to Gardiner, where we’ll be staying the next three nights. In a real hotel!! Tuesday 16 October: Walked around the Mammoth Springs village, built in the early part of last century, with many Art Deco buildings. There are lots of elk around and about, but signs warn not to approach them. We hiked the lower terraces of the massive thermal area above the town. Later drove out to the Lamar Valley for a picnic lunch , and made friends with a raven. Saw big herds of bison throughout the valley. Drove as far as the North East gate of Yellowstone, with beautiful mountain and river views. Wednesday 17 October: Our last day in Yellowstone. We had a look around the Gardiner township, then drove to the Upper Terraces above Mammoth Springs. The drive was still closed due to the icy roads, so we walked the circuit of the upper thermal area. Had a picnic lunch a bit further on next to Lava Creek, then hiked down beside it to Undine Falls and the river below. This time we saw a Grizzly Bear pawprint in the mud! Dinner and beers tonight were at Cowboys Bar. Thursday 18 October: Drove through the Lamar Valley out of Yellowstone, seeing lots more bison along the way. There were a group of wolf spotters up on a hillside, and one of them let us use his field scope to watch a grizzly bear and a pack of wolves. Followed the Chief Joseph Scenic Highway over the mountains. This was the route a Nez Perce tribe took when trying to escape from the US Cavalry into Canada, but they were caught just 30 miles from the border. We watched a group of cowboys moving cattle along the road. One of them had a dog behind his saddle, who would jump down and round up any strays. Travelled to our next stop in Billings Montana, briefly visiting the Moss Mansion, built early last century, and walking around the neighbourhood. We carried on from there to Devil's Tower, Lead/Deadwood, Mt Rushmore, Custer State Park and Badlands NP, before heading to NYC to meet my brother and his family, and spend the Halloween week with them in Bucks County PA. Amazing trip, and we loved it all!