I've been prospecting since 1954 for just about everything. Started looking for placer gold in 1962. The following places are good for color and either partners or I have found gold in quatities large enough to sell.
1. The creeks running off the granite (quartz mononite) formations to the northwest of Tibble Fork reservoir, particularly in Mary Ellen Gulch. Most of the gold I have found is pretty fine (not flour). Back in 1971, Chick Greenalgh, who worked for the Utah County Road Dept. spent a vacation week with his wife working a sluice box and made more that week than he did working a week for the county. He was working a staked claim. So, if you go prospecting there, watch out for claims. Don't be a claim jumper.
2. In the deep creek mountains, in 1964, 1965, 1979 and 1980, I panned in Callao Creek up close to the mountains and found enough fines and small flakes to fill the bottom of a small 15 ml insect specimen vial. There were no staked claims back then. However, since the price of gold has gotten so high, there may be claims. By 1980, there were claims all over the Gold Hill area about 24 miles away on the old Pony Express and Overland Stage road. However there were none on Callao Creek.
3. In the deep creek mountains, in 1964, 1965, 1979 and 1980, I also panned in Trout Creek, about 18 miles southwest of Callao. In gravel bars along the creek in Trout Creek Canyon, I panned out a few small flakes and a picker. I didn't stay long enough to see how much I could get because my main job was selling farm supplies to farmers and ranchers in the area. My last time out that way, in 2012, I didn't notice any claim markers. However further south near the town of Baker and over the Sacramento Pass in Spring Valley, Nevada there were too many claim markers to count and a lot of large-scale dry placer mining.
4. Baker at the Utah state line, around around the mountains, in many dry placers and in most alluvial fans there are nuggets. Some are big ones. I have never found any, but a good friend, Ken Kelly, who worked as a ranger at Lehman Cave, has found several, some close to an ounce. Back around 1978, two Baker brothers (not related to the founder of the town of Baker) unearthed a 7 pound nugget from a dry placer northwest of town. These dry placers are still producing a lot of gold and have produced some truly large nuggets, two very large nuggets from Osceola (about 19 miles from Baker) weighed 23 and 18 pounds respectively. If you go prospecting anywhere around Baker and Wheeler Peak, check carefully for staked claims. These days, they show up as white PVC pipes. Where you don't see claim stakes, watch out for Great Basin National Park, regulations prohibit taking minerals off the National Park area.
5. On either side of highway 50/6 in Sacramento Pass there is still plenty of gold just under the surface in hundreds of dry placers. My friend, Rick Bryan has a claim that has produced so far close to 2,000 ounces of gold. There are many as yet unclaimed dry placers that can be worked with metal detectors and hand equipment in this area.
6. The Snake Range on the border of Utah and Nevada is loaded with gold. Its high peaks were once glaciated and large amounts of gold exist in alluvial fans and glacial outwash. Most of these are dry placers, but several creeks allow for panning and sluicing. There's a mini gold rush going on right now in Utah's west desert, and the Snake Range is part of it. I've only panned in the creeks running into the Snake Valley, but most gravel bars show some color.
7. In the Henry Mountains (named by John Wesley Powell for Smithsonian Secretary Joseph Henry) Crescent Creek, I have noted a lot of coarse gold (flakes, grains) and in separate locations, large amounts of very fine black sand gold, recoverable in sluices with carpets in the bottom. With the high prices for gold, there have been many recent claims staked, but there are still many miles of creek that remain unclaimed. My great grandfather, Samuel Douglass had mining claims there, and every year between 1892 and 1902, he headed south to Eagle City with his son Charles to work his claims and sell dry goods out of the back of his wagon. According to my great-uncle Charley, every year the two of them would leave Payson, Utah in late May with a wagon load of dry goods and horses to sell or trade. They would return in late August with about a thousand pounds of gold ore and placer gold under a false bottom of the wagon. It was turned into cash at the Murray smelter in Salt Lake County. I've been trying to relocate his claims, but no luck so far. His mining company was called the Barefoot, which also had claims in the Spring Mountains near Goodsprings, Nevada, about 32 miles southwest of Las Vegas, Nevada.