The ore tests carried out in Rhyolite were successful, with average values of $37 per ton obtained, and in late January of 1910 the Pennsylvania Company announced definite intentions to build a mill. During February the company began improving the road between its estate and Rhyolite, in order to facilitate the delivery of mill machinery. The Nevada-California Power Company, which was considering the extension of power lines to the Keane Wonder Mine, promised to extend another branch line to the Chloride Cliff mines when the Keane Wonder line was built. In late March the company's small mill arrived and was installed. It was only a one-stamp prospecting mill, with a ten to twelve ton daily capacity, but its purpose was to enable the company to conduct ore tests on the spot. The mine had a small supply of high grade ore, and hoped that by running it through the little mill, funds would be generated to build a larger one. The mill was installed on the side of the cliff below the old Franklin Mine, which was the main group of claims being worked.

By the end of April, the Rhyolite Herald was able to announce that the Chloride Cliff Mine was finally making good. The Pennsylvania Mining and Leasing Company had now expended $10,000 on improvements and developments on the property, and the new mill was installed. Hardly was it placed in operation, however, than the company found that the available water supply was too small to run the mill, and it was shortly abandoned. With its new mill useless, the company shifted gears and proposed to lease one of Rhyolite's idle mills, and to haul its ore into town for reduction there.

But developments came slowly. The company succeeded in leasing the Crystal Bullfrog Mill at Rhyolite, and obtained a 12-horse team to haul ore to the mill site, but as June stretched into July, no ore shipments were made. The company was employing eight miners at the mine, but developments proceeded at a rather slow pace. In the meantime, the Pennsylvania Mining and Leasing Company was undergoing internal reorganization, and in August J. Irving Crowell, president of the Chloride Cliff Mining Company, emerged as president of the Pennsylvania Company. Crowell was thus in charge of the company which was leasing ground from the mining company of which he was also president.

After the reorganization, activities quickened. One hundred tons of ore were treated at the Crystal Bullfrog Mill in August, and Crowell announced that the mine could keep the mill well supplied for quite some time. Average values of the ore taken to the mill were $35 per ton, and the mill reported savings of 90 percent of the value of the ore. Taking these figures, the mine should have received returns of $3,250 for the ore which was treated in August. With the initial successes, the company announced plans to increase its ore shipments in the near future, and searched for more horse teams to haul ore. The company still owned a good water right about three miles from the mine, but the cost of installing pipe and pumping water uphill to the mine would be high. Nevertheless, the company planned to do just that, provided that the ore values in the mine held up with development. Although sporadic work was being done on all the company's claims, the main mining effort was still being concentrated on the old Franklin Mine.

From August to October of 1910, the company continued to work. Ore output was increased, and the company soon had four sets of horse teams hauling ore from the mine to the mill. The dumps at the mine contained over 200 tons of milling ore, and seven tons were delivered to the mill each day. During September, the Pennsylvania Mining and Leasing Company also began to ship some high-grade ore directly to the smelters at Needles, California and Goldfield, Nevada. Then, in the middle of October, work stopped while more plans were made.

The company announced that it had decided to enlarge its own one-stamp mill at Chloride Cliff. Three hundred tons of ore had by now been processed at the Crystal Bullfrog Mill, but the average mill savings had only been 60 percent on the average $30 ore. The company was obviously losing much of its ore content, which it could not afford to do. The company planned to continue sending selected high-grade ores directly to the smelters, but would add two. more stamps to its own mill, as well as concentrating tables and cyanidation treatment. Water development was in progress at the company's source near Keane Springs, and the enlargement of the mill was of necessity dependent upon the delivery of water to the mill site. To do this, the Pennsylvania Company intended to install a four-mile pipe line and a pump at the springs. The costs would be high, but J. Irving Crowell stated that the ore uncoverings in the mine justified this kind of expenditure. The Rhyolite Herald supported Crowell's plans, for more development meant more work for local miners. Although only nine men were employed at the Franklin Mine, the company had hired as many as nineteen while ore shipments were being made, and the enlargement of the mill at Chloride Cliff would mean work for double that number of miners.

As often happens, when a mine ceased work in order to develop future operations plans, it really meant that the company had no clear idea of what to do next. This was the case of the Chloride Cliff Mining Company and the Pennsylvania Mining and Leasing Company. Neither company had the resources to develop a small and isolated mine into a paying proposition, even if there was enough ore in the ground to warrant such expenditures. As a result, the Pennsylvania Company let its lease expire, and the mine lay idle as the Chloride Cliff Company searched for another source of capital. The solution was not found until April of 1911, when it was announced that the Chloride Cliff property was to be sold to an English corporation "of considerable financial strength."