Alaska – It goes without saying that Mount McKinley requires lots of preparation. The climbing process is heavily regulated and they are considering quotas. For more info: http://www.nps.gov/dena/mountain/talkeet.htm
California – Entry into the “Whitney Zone” is heavily regulated. The quotas were reduced in 2001. If you want to camp on the mountain you need to enter a lottery stating your dates in February. If you just want to dayhike you also need a permit. The permits are also in the February lottery and if you are planning on visiting on weekends in August you should apply then. The permits are more easily obtained for other days of the week. More info: http://www.fs.fed.us/r5/inyo/recreation/mt_whitney.html
Hawaii – While Hawai’i is a drive up there are constantly battles over restricting access to the summit. Astronomers do not want you to driving up after dark. Limits have been imposed on the commercial group size that summit. Further, many car rental companies prohibit cars from driving on Saddle Road and the mountain.
Maine – Baxter State Park has very strict rules on access and quotas on the trails. You can find out more at: http://www.mainerec.com/baxter1.asp?Category=101&PageNum=101
New York – The New York DEC is considering imposing quotas on Marcy and other high peaks. There are restrictions on group size and parking. Further, New York traditionally requests you do not climb the High Peaks during May and the first couple weeks of June to avoid damaging muddy trails. For more info check out: http://www.adk.org/html/high_peaks_wilderness_area_access.html
Ohio – The highpoint is owned by the Hi Point Vocational School and is inside a gated compound. The compound is open during daylight on weekdays. However if you make prior arrangements the pedestrian gate on the left of the main gate will be left open. In order to make these arrangement you should call (937) 599-3010 on weekdays been 7 a.m. and 3 p.m.
Oregon – Mount Hood is currently a marginal yellow flag. Proposals are on the table to impose quotas. Currently, you only need a free self-issue permit. However, Hood can be extremely dangerous and it is advised that you only climb during the May to mid-July season. More info: http://www.fs.fed.us/r6/mthood/climb99.htm
Vermont – Vermont has asked that you voluntarily not climb Mount Mansfield during May and the first week of June to avoid damaging soggy trails.
Washington – Rainier is considering closing its Paradise Parking Lot to climbers (climbers would have to be shuttled to and from the trailhead). Currently, the only official regulation is the $15 climbing fee. More info: http://www.nps.gov/mora/