I like these kinds of lists. They're more specific to a person than the generic "100 Things...". Items in italics have not yet been accomplished.
1. See an erupting volcano. - Yeah, it's a goal. The main reason I want to go to Hawaii. And that just shows how weird I truly am.
2. See a glacier. - Since I'm guessing from closer up than Mt. Shasta from I-5, I have to say "Not Yet."
3. See an active geyser such as those in Yellowstone, New Zealand or the type locality of Iceland. - Again, not quite. Little Hot Creek in Long Valley and its little hot pots don't quite count.
4. Visit the Cretaceous/Tertiary (KT) Boundary. Possible locations include Gubbio, Italy; Stevns Klint, Denmark; the Red Deer River Valley near Drumheller, Alberta. - Nope.
5. Observe (from a safe distance) a river whose discharge is above bankful stage. - Was this last year or the year before? It was New Years Day when Grayson Creek flooded in Pacheco. And I'm guessing that being on the bridge spanning the creek is not necessarily at a safe distance.
6. Explore a limestone cave. Try Carlsbad Caverns in New Mexico, Lehman Caves in Great Basin National Park, or the caves of Kentucky or TAG (Tennessee, Alabama, and Georgia). - I got to take a night tour through Mammoth Cave in Kentucky while out there for grad school. It's an awesome sight.
7. Tour an open pit mine, such as those in Butte, Montana, Bingham Canyon, Utah, Summitville, Colorado, Globe or Morenci, Arizona, or Chuquicamata, Chile. - Outside of Getchell, Nevada, for my Ore Deposits course at Sacramento State. We saw a few pits, and got to enter one of them. It dwarfed any stadium I've been in including parking lots. And there was a one in thick layer of crystalline barite about halfway up the walls.
8. Explore a subsurface mine. - This time for ore deposits and then field mapping at Sac. The first was a large modern gold mine near Jackson Slough. The shaft was only slightly inclined (more of a long adit), but was big enough for two large dump trucks to use. Lots of quartz veins in black slate. The other was an old gold mine in Placerville. Narrow and irregular, but beautiful walls of mariposite.
9. See an ophiolite, such as the ophiolite complex in Oman or the Troodos complex on the Island Cyprus (if on a budget, try the Coast Ranges or Klamath Mountains of California). - Every time I drive to Point Reyes, or the Marin Headlands I get to see this.
10. An anorthosite complex, such as those in Labrador, the Adirondacks, and Niger (there's some anorthosite in southern California too). - Not yet.
11. A slot canyon. Many of these amazing canyons are less than 3 feet wide and over 100 feet deep. They reside on the Colorado Plateau. Among the best are Antelope Canyon, Brimstone Canyon, Spooky Gulch and the Round Valley Draw. - Hopefully soon.
12. Varves, whether you see the type section in Sweden or examples elsewhere. - I actually got to see a small example outside of Livermore doing a fault trench. We came across a small pond that had obvious varves.
13. An exfoliation dome, such as those in the Sierra Nevada. - Yup. And Rock City on Mt. Diablo.
14. A layered igneous intrusion, such as the Stillwater complex in Montana or the Skaergaard Complex in Eastern Greenland. - Nope.
15. Coastlines along the leading and trailing edge of a tectonic plate (check out The Dynamic Earth - The Story of Plate Tectonics - an excellent website). - Yup.
16. A gingko tree, which is the lone survivor of an ancient group of softwoods that covered much of the Northern Hemisphere in the Mesozoic. - I actually have one in a pot beside my garage, but Sac State had scores of them; unfortunately both male and female, so the stench was quite overwhelming in the spring. And we had on in the yard in Kentucky when I was in high school.
17. Living and fossilized stromatolites (Glacier National Park is a great place to see fossil stromatolites, while Shark Bay in Australia is the place to see living ones) - Yeah, but I can't remember where I was.
18. A field of glacial erratics. - Not a field no.
19. A caldera. - Long Valley. Not all at once of course, but we traveled over most of the caldera. And sometime this year, Jennifer and I have plans to go to Crater Lake.
20. A sand dune more than 200 feet high. - Nope.
21. A fjord. - No.
22. A recently formed fault scarp. - Only in pictures.
23. A megabreccia. - No.
24. An actively accreting river delta. - Yes, I'm sure, but no specific examples come to mind.
25. A natural bridge. - No.
26. A large sinkhole. - Back in Kentucky.
27. A glacial outwash plain. - Long Valley again. There are quite a few.
28. A sea stack. - Plenty along the California coast.
29. A house-sized glacial erratic. - No.
30. An underground lake or river. - In the Mammoth Cave complex.
31. The continental divide - Many times from driving cross-country from California to Kentucky.
32. Fluorescent and phosphorescent minerals. - Lately at a rock and mineral show, but also in both my mineralogy and ore deposits courses.
33. Petrified trees. - In a museum and I've some pieces, but never in nature.
34. Lava tubes. - The jets near Depoe Bay in Oregon are believed to be formed by tidal water being forced into lava tubes. But I have yet to walk through any.
35. The Grand Canyon. All the way down. And back. - No. When I returned to California from Kentucky, the Grand Canyon was not yet completed, and the far side was shrouded in fog. I hope to return, but there's no way I'm walking on the transparent walkway.
36. Meteor Crater, Arizona, also known as the Barringer Crater, to see an impact crater on a scale that is comprehensible. - Hopefully when I return to the Grand Canyon.
37. The Great Barrier Reef, northeastern Australia, to see the largest coral reef in the world. - No.
38. The Bay of Fundy, New Brunswick and Nova Scotia, Canada, to see the highest tides in the world (up to 16m). - No.
39. The Waterpocket Fold, Utah, to see well exposed folds on a massive scale. - No.
40. The Banded Iron Formation, Michigan, to better appreciate the air you breathe. - No.
41. The Snows of Kilimanjaro, Tanzania. - No.
42. Lake Baikal, Siberia, to see the deepest lake in the world (1,620 m) with 20 percent of the Earth's fresh water. - No.
43. Ayers Rock (known now by the Aboriginal name of Uluru), Australia. This inselberg of nearly vertical Precambrian strata is about 2.5 kilometers long and more than 350 meters high. - No.
44. Devil's Tower, northeastern Wyoming, to see a classic example of columnar jointing. - No, but I've seen the jointing in the Bishop Tuff in Long Valley.
45. The Alps. - No.
46. Telescope Peak, in Death Valley National Park. From this spectacular summit you can look down onto the floor of Death Valley - 11,330 feet below. - No.
47. The Li River, China, to see the fantastic tower karst that appears in much Chinese art. - No.
48. The Dalmation Coast of Croatia, to see the original Karst. - No.
49. The Gorge of Bhagirathi, one of the sacred headwaters of the Ganges, in the Indian Himalayas, where the river flows from an ice tunnel beneath the Gangatori Glacier into a deep gorge. - No.
50. The Goosenecks of the San Juan River, Utah, an impressive series of entrenched meanders. - No.
51. Shiprock, New Mexico, to see a large volcanic neck. - No.
52. Land's End, Cornwall, Great Britain, for fractured granites that have feldspar crystals bigger than your fist. - No.
53. Tierra del Fuego, Chile and Argentina, to see the Straights of Magellan and the southernmost tip of South America. - And perhaps the Flying Dutchman.
54. Mount St. Helens, Washington, to see the results of recent explosive volcanism. - Only from a distance. Someday I need to go to Oregon during good weather.
55. The Giant's Causeway and the Antrim Plateau, Northern Ireland, to see polygonally fractured basaltic flows. - No, but definitely a goal.
56. The Great Rift Valley in Africa. - No.
57. The Matterhorn, along the Swiss/Italian border, to see the classic "horn". - No.
58. The Carolina Bays, along the Carolinian and Georgian coastal plain. - Yes, in high school, but I didn't know why they were special at the time.
59. The Mima Mounds near Olympia, Washington. - No.
60. Siccar Point, Berwickshire, Scotland, where James Hutton (the "father" of modern geology) observed the classic unconformity. - No.
61. The moving rocks of Racetrack Playa in Death Valley. - Also something to see soon.
62. Yosemite Valley. - Twice. I've even been fortunate enough to see the sno-cone under Yosemite Falls.
63. Landscape Arch (or Delicate Arch) in Utah. - No.
64. The Burgess Shale in British Columbia. - No.
65. The Channeled Scablands of central Washington. - No.
66. Bryce Canyon. - No.
67. Grand Prismatic Spring at Yellowstone. - No, and I just need to get to Yellowstone period.
68. Monument Valley. - No.
69. The San Andreas fault. - I've flown parallel to it many times, and I've seen the offset fence many times at Point Reyes Station.
70. The dinosaur footprints in La Rioja, Spain. - No.
71. The volcanic landscapes of the Canary Islands. - No.
72. The Pyrenees Mountains. - No.
73. The Lime Caves at Karamea on the West Coast of New Zealand. - No.
74. Denali (an orogeny in progress). - No, but my uncle has climbed it.
75. A catastrophic mass wasting event. - You mean besides all the ones I created my climbing during summer and winter field? I have seen many collapsed slopes along the Oakland Hills and certain housing projects throughout the Bay Area.
76. The giant crossbeds visible at Zion National Park. - No.
77. The black sand beaches in Hawaii (or the green sand-olivine beaches). - No, but Jennifer brought me back some sand.
78. Barton Springs in Texas. - No.
79. Hells Canyon in Idaho. - No.
80. The Black Canyon of the Gunnison in Colorado. - No.
81. The Tunguska Impact site in Siberia. - No, but oh, so tempting.
82. Feel an earthquake with a magnitude greater than 5.0. - Yeah this has happened a few times. Especially back when the Hayward Fault was overly active in the late 70s and early 80s. I was in Sac during Loma Prieta, and Zzyzx during Northridge, so I've missed recent the big ones.
83. Find dinosaur footprints in situ. - No.
84. Find a trilobite (or a dinosaur bone or any other fossil). - Lots of brachiopods in the road cuts on the road from Lexington to Maysville.
85. Find gold, however small the flake. - Panning in the Sierra Nevada.
86. Find a meteorite fragment. - No.
87. Experience a volcanic ash fall. - Only the fringe, but the dust content was high after Mt. St. Helens.
88. Experience a sandstorm. - Driving from California to Kentucky for grad school, my cousin and I went through one in Utah.
89. See a tsunami. - No.
90. Witness a total solar eclipse. - No.
91. Witness a tornado firsthand. (Important rules of this game). - Bugger you chasing, I've had one jump my subdivision when I was a kid. I've seen the green sky and clouds, and seen a funnel dropping.
92. Witness a meteor storm, a term used to describe a particularly intense (1000+ per minute) meteor shower. - No, the Perseids and Leonids have yet to be that exciting.
93. View Saturn and its moons through a respectable telescope. - Chabot baby.
94. See the Aurora borealis, otherwise known as the northern lights. - Not yet, but I've got Jennifer very excited to see these.
95. View a great naked-eye comet, an opportunity which occurs only a few times per century - Comet Hyakutate. We saw it naked eye while walking to Dairy Queen drunk during a party.
96. See a lunar eclipse. - Hard not to really.
97. View a distant galaxy through a large telescope. - Andromeda, and others at Chabot.
98. Experience a hurricane - Hurricane Gloria during my Junior year of high school, Fall 1985. I'd had snow days and ice days in Kentucky and heat days in California, but it took a year in Maryland to have a hurricane day.
99. See noctilucent clouds. - Yes. Another bonus of living near the coast.
100. See the green flash. - It's debatable, so I'm guessing no.