It's a little complicated. They are all National Forest Service units, and you can get into them all with an NFS Day Pass ($5 per day) or Interagency Pass ($20/yr for seniors, $80/day otherwise). These passes allow the pass holder and any accompanying passengers in a private vehicle use of the recreation facilities unless the facility is on a per-person basis. There is also a "Newberry National Volcanic Monument 3-Day Pass" at $5/day. It gets you into the NNVM, including the Visitors Center, but not into Deschutes National Forest. Google the phrase, and the web page and its links describe full details of both types of passes. NOTE: The Visitors Center is scheduled to open for 2020 on May 1 through November 1.

Should be i am not sure. Check out

For 2019, the website says: "October 7, Visitor Center is CLOSED to the public for the season. Parking for trail access remains open." "The parking area for the visitor's center is open year-round, and access is dependent upon snow accumulations during winter months." For more details, find the website by googling Lava Lands Visitor Center.

If you are just interested in touring the Visitor's Center, that could be done in an hour but there are trails on site and if you'd like to visit some of those you would probably want to allow at least a few hours. If you'd also like to visit the top of the Lava Butte, you will receive time slip when you check in, then plan to be at the top at the time you are given. There is a one mile trail around the top of the volcano. During the busy summer months, you will take a bus to the top as the parking lot up there is very small.

The lava tube is an easy walk with the flashlight but uneven services so you just have to be careful and keep the light well lit. Good batteries. I think it was a mile down and a mile back. But you don't have to go all the way to get an idea. That was indoors, so not hot. The outdoor trails were extremely hot because of the black lava rock around, we did not go very far on those. Hope that helps

The new bus that takes you up to the top of the butte costs, I think, about $3 per person. It's a new function of the park because there is so little parking up there and the road is narrow. You can stay up there as long as you want; the bus comes and goes every 20 minutes until the last trip at 4:30 pm.